20155132240 has 80 divisors (see below), whose sum is σ = 49021750800. Its totient is φ = 7696510976.

The previous prime is 20155132237. The next prime is 20155132243. The reversal of 20155132240 is 4223155102.

It is an interprime number because it is at equal distance from previous prime (20155132237) and next prime (20155132243).

It can be written as a sum of positive squares in 8 ways, for example, as 7033104 + 20148099136 = 2652^2 + 141944^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×20155132240² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20155132243) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 157674 + ... + 255286.

It is an arithmetic number, because the mean of its divisors is an integer number (612771885).

Almost surely, 2^20155132240 is an apocalyptic number.

20155132240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20155132240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24510875400).

20155132240 is an abundant number, since it is smaller than the sum of its proper divisors (28866618560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20155132240 is a wasteful number, since it uses less digits than its factorization.

20155132240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97744 (or 97738 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

Adding to 20155132240 its reverse (4223155102), we get a palindrome (24378287342).

The spelling of 20155132240 in words is "twenty billion, one hundred fifty-five million, one hundred thirty-two thousand, two hundred forty".