87691905 has 24 divisors (see below), whose sum is σ = 173714112. Its totient is φ = 40087584.

The previous prime is 87691889. The next prime is 87691909. The reversal of 87691905 is 50919678.

It is not a de Polignac number, because 87691905 - 2⁴ = 87691889 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (87691909) 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, 138879 + ... + 139508.

It is an arithmetic number, because the mean of its divisors is an integer number (7238088).

Almost surely, 2^87691905 is an apocalyptic number.

It is an amenable number.

87691905 is a deficient number, since it is larger than the sum of its proper divisors (86022207).

87691905 is a wasteful number, since it uses less digits than its factorization.

87691905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278405 (or 278402 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The square root of 87691905 is about 9364.3956024935. The cubic root of 87691905 is about 444.2763223955.

The spelling of 87691905 in words is "eighty-seven million, six hundred ninety-one thousand, nine hundred five".