18612978 has 16 divisors (see below), whose sum is σ = 37464960. Its totient is φ = 6164496.

The previous prime is 18612973. The next prime is 18613009. The reversal of 18612978 is 87921681.

It is not an unprimeable number, because it can be changed into a prime (18612973) 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, 8938 + ... + 10821.

It is an arithmetic number, because the mean of its divisors is an integer number (2341560).

Almost surely, 2^18612978 is an apocalyptic number.

18612978 is an abundant number, since it is smaller than the sum of its proper divisors (18851982).

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

18612978 is a wasteful number, since it uses less digits than its factorization.

18612978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19921.

The product of its digits is 48384, while the sum is 42.

The square root of 18612978 is about 4314.2760690526. The cubic root of 18612978 is about 265.0159145539.

The spelling of 18612978 in words is "eighteen million, six hundred twelve thousand, nine hundred seventy-eight".