20645251500431 has 4 divisors (see below), whose sum is σ = 21125373628392. Its totient is φ = 20165129372472.

The previous prime is 20645251500413. The next prime is 20645251500473. The reversal of 20645251500431 is 13400515254602.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20645251500431 - 2²⁶ = 20645184391567 is a prime.

It is a super-2 number, since 2×20645251500431² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20645251502431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 240061063916 + ... + 240061064001.

It is an arithmetic number, because the mean of its divisors is an integer number (5281343407098).

Almost surely, 2^{20645251500431} is an apocalyptic number.

20645251500431 is a deficient number, since it is larger than the sum of its proper divisors (480122127961).

20645251500431 is an equidigital number, since it uses as much as digits as its factorization.

20645251500431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 480122127960.

The product of its (nonzero) digits is 144000, while the sum is 38.

The spelling of 20645251500431 in words is "twenty trillion, six hundred forty-five billion, two hundred fifty-one million, five hundred thousand, four hundred thirty-one".