20531154240 has 280 divisors, whose sum is σ = 76210485120. Its totient is φ = 5236780032.

The previous prime is 20531154233. The next prime is 20531154251. The reversal of 20531154240 is 4245113502.

20531154240 is a `hidden beast` number, since 20 + 53 + 11 + 542 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 578941 + ... + 613379.

It is an arithmetic number, because the mean of its divisors is an integer number (272180304).

Almost surely, 2^20531154240 is an apocalyptic number.

20531154240 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 20531154240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38105242560).

20531154240 is an abundant number, since it is smaller than the sum of its proper divisors (55679330880).

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

20531154240 is a wasteful number, since it uses less digits than its factorization.

20531154240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34491 (or 34472 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

Adding to 20531154240 its reverse (4245113502), we get a palindrome (24776267742).

The spelling of 20531154240 in words is "twenty billion, five hundred thirty-one million, one hundred fifty-four thousand, two hundred forty".