87821490 has 32 divisors (see below), whose sum is σ = 223171200. Its totient is φ = 22041344.

The previous prime is 87821479. The next prime is 87821491. The reversal of 87821490 is 9412878.

It is a super-2 number, since 2×87821490² = 15425228211640200, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (87821491) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85590 + ... + 86609.

It is an arithmetic number, because the mean of its divisors is an integer number (6974100).

Almost surely, 2^87821490 is an apocalyptic number.

87821490 is an abundant number, since it is smaller than the sum of its proper divisors (135349710).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

87821490 is a wasteful number, since it uses less digits than its factorization.

87821490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172226.

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 87821490 is about 9371.3120746243. The cubic root of 87821490 is about 444.4950549079.

The spelling of 87821490 in words is "eighty-seven million, eight hundred twenty-one thousand, four hundred ninety".