87210921 has 8 divisors (see below), whose sum is σ = 132892864. Its totient is φ = 49834800.

The previous prime is 87210913. The next prime is 87210953. The reversal of 87210921 is 12901278.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 87210921 - 2³ = 87210913 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87210971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2076430 + ... + 2076471.

It is an arithmetic number, because the mean of its divisors is an integer number (16611608).

Almost surely, 2^87210921 is an apocalyptic number.

It is an amenable number.

87210921 is a deficient number, since it is larger than the sum of its proper divisors (45681943).

87210921 is a wasteful number, since it uses less digits than its factorization.

87210921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4152911.

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 87210921 is about 9338.6787609383. The cubic root of 87210921 is about 443.4625578534.

The spelling of 87210921 in words is "eighty-seven million, two hundred ten thousand, nine hundred twenty-one".