71561402531 has 2 divisors, whose sum is σ = 71561402532. Its totient is φ = 71561402530.

The previous prime is 71561402513. The next prime is 71561402587. The reversal of 71561402531 is 13520416517.

It is a happy number.

Together with previous prime (71561402513) 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 a de Polignac number, because none of the positive numbers 2^k-71561402531 is a prime.

It is a super-2 number, since 2×71561402531² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 71561402491 and 71561402500.

It is not a weakly prime, because it can be changed into another prime (71561402831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35780701265 + 35780701266.

It is an arithmetic number, because the mean of its divisors is an integer number (35780701266).

Almost surely, 2^71561402531 is an apocalyptic number.

71561402531 is a deficient number, since it is larger than the sum of its proper divisors (1).

71561402531 is an equidigital number, since it uses as much as digits as its factorization.

71561402531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25200, while the sum is 35.

The spelling of 71561402531 in words is "seventy-one billion, five hundred sixty-one million, four hundred two thousand, five hundred thirty-one".