87381640 has 32 divisors (see below), whose sum is σ = 203391000. Its totient is φ = 33746944.

The previous prime is 87381631. The next prime is 87381643. The reversal of 87381640 is 4618378.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 52736644 + 34644996 = 7262^2 + 5886^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 87381640.

It is not an unprimeable number, because it can be changed into a prime (87381643) 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, 36505 + ... + 38824.

Almost surely, 2^87381640 is an apocalyptic number.

It is an amenable number.

87381640 is an abundant number, since it is smaller than the sum of its proper divisors (116009360).

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

87381640 is a wasteful number, since it uses less digits than its factorization.

87381640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75369 (or 75365 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 87381640 is about 9347.8147178900. The cubic root of 87381640 is about 443.7517347019.

The spelling of 87381640 in words is "eighty-seven million, three hundred eighty-one thousand, six hundred forty".