87906356953921 has 27 divisors (see below), whose sum is σ = 99043278545449. Its totient is φ = 77961976452800.

The previous prime is 87906356953897. The next prime is 87906356953931. The reversal of 87906356953921 is 12935965360978.

The square root of 87906356953921 is 9375839.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 1415240950321 + 86491116003600 = 1189639^2 + 9300060^2 .

It is a de Polignac number, because none of the positive numbers 2^k-87906356953921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87906356953931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4228492995 + ... + 4228513783.

Almost surely, 2^{87906356953921} is an apocalyptic number.

87906356953921 is the 9375839-th square number.

87906356953921 is the 4687920-th centered octagonal number.

It is an amenable number.

87906356953921 is a deficient number, since it is larger than the sum of its proper divisors (11136921591528).

87906356953921 is an frugal number, since it uses more digits than its factorization.

87906356953921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41682 (or 20841 counting only the distinct ones).

The product of its (nonzero) digits is 661348800, while the sum is 73.

The spelling of 87906356953921 in words is "eighty-seven trillion, nine hundred six billion, three hundred fifty-six million, nine hundred fifty-three thousand, nine hundred twenty-one".