87817978 has 16 divisors (see below), whose sum is σ = 137846016. Its totient is φ = 41908320.

The previous prime is 87817973. The next prime is 87818011. The reversal of 87817978 is 87971878.

It is not an unprimeable number, because it can be changed into a prime (87817973) 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, 5176 + ... + 14227.

It is an arithmetic number, because the mean of its divisors is an integer number (8615376).

Almost surely, 2^87817978 is an apocalyptic number.

87817978 is a deficient number, since it is larger than the sum of its proper divisors (50028038).

87817978 is a wasteful number, since it uses less digits than its factorization.

87817978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19509.

The product of its digits is 1580544, while the sum is 55.

The square root of 87817978 is about 9371.1246923728. The cubic root of 87817978 is about 444.4891296784.

The spelling of 87817978 in words is "eighty-seven million, eight hundred seventeen thousand, nine hundred seventy-eight".