20157537665251 has 12 divisors (see below), whose sum is σ = 23541984811800. Its totient is φ = 17209053204000.

The previous prime is 20157537665233. The next prime is 20157537665281. The reversal of 20157537665251 is 15256673575102.

It is not a de Polignac number, because 20157537665251 - 2¹⁵ = 20157537632483 is a prime.

It is a super-2 number, since 2×20157537665251² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20157537665192 and 20157537665201.

It is not an unprimeable number, because it can be changed into a prime (20157537665201) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 819466426 + ... + 819491023.

It is an arithmetic number, because the mean of its divisors is an integer number (1961832067650).

Almost surely, 2^{20157537665251} is an apocalyptic number.

20157537665251 is a deficient number, since it is larger than the sum of its proper divisors (3384447146549).

20157537665251 is a wasteful number, since it uses less digits than its factorization.

20157537665251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1638957714 (or 1638957707 counting only the distinct ones).

The product of its (nonzero) digits is 13230000, while the sum is 55.

The spelling of 20157537665251 in words is "twenty trillion, one hundred fifty-seven billion, five hundred thirty-seven million, six hundred sixty-five thousand, two hundred fifty-one".