20645251502431 has 2 divisors, whose sum is σ = 20645251502432. Its totient is φ = 20645251502430.

The previous prime is 20645251502423. The next prime is 20645251502461. The reversal of 20645251502431 is 13420515254602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20645251502431 - 2³ = 20645251502423 is a prime.

It is a super-2 number, since 2×20645251502431² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20645251502461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10322625751215 + 10322625751216.

It is an arithmetic number, because the mean of its divisors is an integer number (10322625751216).

Almost surely, 2^{20645251502431} is an apocalyptic number.

20645251502431 is a deficient number, since it is larger than the sum of its proper divisors (1).

20645251502431 is an equidigital number, since it uses as much as digits as its factorization.

20645251502431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288000, while the sum is 40.

The spelling of 20645251502431 in words is "twenty trillion, six hundred forty-five billion, two hundred fifty-one million, five hundred two thousand, four hundred thirty-one".