87567921 has 24 divisors (see below), whose sum is σ = 146600064. Its totient is φ = 49331520.

The previous prime is 87567917. The next prime is 87567947. The reversal of 87567921 is 12976578.

87567921 is a `hidden beast` number, since 87 + 567 + 9 + 2 + 1 = 666.

It is not a de Polignac number, because 87567921 - 2² = 87567917 is a prime.

It is a super-4 number, since 4×87567921⁴ (a number of 33 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (87567911) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5316 + ... + 14261.

It is an arithmetic number, because the mean of its divisors is an integer number (6108336).

Almost surely, 2^87567921 is an apocalyptic number.

It is an amenable number.

87567921 is a deficient number, since it is larger than the sum of its proper divisors (59032143).

87567921 is a wasteful number, since it uses less digits than its factorization.

87567921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19661 (or 19658 counting only the distinct ones).

The product of its digits is 211680, while the sum is 45.

The square root of 87567921 is about 9357.7732928299. The cubic root of 87567921 is about 444.0668422620.

It can be divided in two parts, 87567 and 921, that added together give a palindrome (88488).

The spelling of 87567921 in words is "eighty-seven million, five hundred sixty-seven thousand, nine hundred twenty-one".