87213569 has 2 divisors, whose sum is σ = 87213570. Its totient is φ = 87213568.

The previous prime is 87213563. The next prime is 87213617. The reversal of 87213569 is 96531278.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84364225 + 2849344 = 9185^2 + 1688^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87213569 is a prime.

It is a super-2 number, since 2×87213569² = 15212413235435522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (87213563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43606784 + 43606785.

It is an arithmetic number, because the mean of its divisors is an integer number (43606785).

Almost surely, 2^87213569 is an apocalyptic number.

It is an amenable number.

87213569 is a deficient number, since it is larger than the sum of its proper divisors (1).

87213569 is an equidigital number, since it uses as much as digits as its factorization.

87213569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 41.

The square root of 87213569 is about 9338.8205358064. The cubic root of 87213569 is about 443.4670461176.

It can be divided in two parts, 872 and 13569, that added together give a palindrome (14441).

The spelling of 87213569 in words is "eighty-seven million, two hundred thirteen thousand, five hundred sixty-nine".