20508492451 has 2 divisors, whose sum is σ = 20508492452. Its totient is φ = 20508492450.

The previous prime is 20508492443. The next prime is 20508492503. The reversal of 20508492451 is 15429480502.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20508492451 - 2³ = 20508492443 is a prime.

It is a super-2 number, since 2×20508492451² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20508492551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10254246225 + 10254246226.

It is an arithmetic number, because the mean of its divisors is an integer number (10254246226).

Almost surely, 2^20508492451 is an apocalyptic number.

20508492451 is a deficient number, since it is larger than the sum of its proper divisors (1).

20508492451 is an equidigital number, since it uses as much as digits as its factorization.

20508492451 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 115200, while the sum is 40.

The spelling of 20508492451 in words is "twenty billion, five hundred eight million, four hundred ninety-two thousand, four hundred fifty-one".