20155187240 has 16 divisors (see below), whose sum is σ = 45349171380. Its totient is φ = 8062074880.

The previous prime is 20155187207. The next prime is 20155187243. The reversal of 20155187240 is 4278155102.

It can be written as a sum of positive squares in 2 ways, for example, as 19840976164 + 314211076 = 140858^2 + 17726^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20155187240.

It is not an unprimeable number, because it can be changed into a prime (20155187243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 251939801 + ... + 251939880.

Almost surely, 2^20155187240 is an apocalyptic number.

20155187240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20155187240 is an abundant number, since it is smaller than the sum of its proper divisors (25193984140).

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

20155187240 is a wasteful number, since it uses less digits than its factorization.

20155187240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 503879692 (or 503879688 counting only the distinct ones).

The product of its (nonzero) digits is 22400, while the sum is 35.

The spelling of 20155187240 in words is "twenty billion, one hundred fifty-five million, one hundred eighty-seven thousand, two hundred forty".