87565135421 has 2 divisors, whose sum is σ = 87565135422. Its totient is φ = 87565135420.

The previous prime is 87565135393. The next prime is 87565135547. The reversal of 87565135421 is 12453156578.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76668072100 + 10897063321 = 276890^2 + 104389^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87565135421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87565125421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43782567710 + 43782567711.

It is an arithmetic number, because the mean of its divisors is an integer number (43782567711).

Almost surely, 2^87565135421 is an apocalyptic number.

It is an amenable number.

87565135421 is a deficient number, since it is larger than the sum of its proper divisors (1).

87565135421 is an equidigital number, since it uses as much as digits as its factorization.

87565135421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1008000, while the sum is 47.

The spelling of 87565135421 in words is "eighty-seven billion, five hundred sixty-five million, one hundred thirty-five thousand, four hundred twenty-one".