20178395131 has 2 divisors, whose sum is σ = 20178395132. Its totient is φ = 20178395130.

The previous prime is 20178395113. The next prime is 20178395173. The reversal of 20178395131 is 13159387102.

Together with previous prime (20178395113) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20178395131 - 2²⁵ = 20144840699 is a prime.

It is a super-2 number, since 2×20178395131² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20178195131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10089197565 + 10089197566.

It is an arithmetic number, because the mean of its divisors is an integer number (10089197566).

Almost surely, 2^20178395131 is an apocalyptic number.

20178395131 is a deficient number, since it is larger than the sum of its proper divisors (1).

20178395131 is an equidigital number, since it uses as much as digits as its factorization.

20178395131 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45360, while the sum is 40.

The spelling of 20178395131 in words is "twenty billion, one hundred seventy-eight million, three hundred ninety-five thousand, one hundred thirty-one".