87372856921 has 9 divisors (see below), whose sum is σ = 101640220149. Its totient is φ = 74889246684.

The previous prime is 87372856913. The next prime is 87372856927. The reversal of 87372856921 is 12965827378.

It is a happy number.

The square root of 87372856921 is 295589.

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

It is not a de Polignac number, because 87372856921 - 2³ = 87372856913 is a prime.

It is a super-2 number, since 2×87372856921² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87372856927) 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 8 ways as a sum of consecutive naturals, for example, 2048010 + ... + 2090236.

Almost surely, 2^87372856921 is an apocalyptic number.

87372856921 is the 295589-th square number.

87372856921 is the 147795-th centered octagonal number.

It is an amenable number.

87372856921 is a deficient number, since it is larger than the sum of its proper divisors (14267363228).

87372856921 is an frugal number, since it uses more digits than its factorization.

87372856921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84468 (or 42234 counting only the distinct ones).

The product of its digits is 10160640, while the sum is 58.

The spelling of 87372856921 in words is "eighty-seven billion, three hundred seventy-two million, eight hundred fifty-six thousand, nine hundred twenty-one".