87156021 has 8 divisors (see below), whose sum is σ = 122324320. Its totient is φ = 55045872.

The previous prime is 87156019. The next prime is 87156023. The reversal of 87156021 is 12065178.

It is an interprime number because it is at equal distance from previous prime (87156019) and next prime (87156023).

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

It is not a de Polignac number, because 87156021 - 2¹ = 87156019 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 87156021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87156023) 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, 764470 + ... + 764583.

It is an arithmetic number, because the mean of its divisors is an integer number (15290540).

Almost surely, 2^87156021 is an apocalyptic number.

It is an amenable number.

87156021 is a deficient number, since it is larger than the sum of its proper divisors (35168299).

87156021 is a wasteful number, since it uses less digits than its factorization.

87156021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1529075.

The product of its (nonzero) digits is 3360, while the sum is 30.

The square root of 87156021 is about 9335.7389102309. The cubic root of 87156021 is about 443.3694838644.

The spelling of 87156021 in words is "eighty-seven million, one hundred fifty-six thousand, twenty-one".