18969978 has 16 divisors (see below), whose sum is σ = 38507040. Its totient is φ = 6228816.

The previous prime is 18969971. The next prime is 18969983. The reversal of 18969978 is 87996981.

It is not an unprimeable number, because it can be changed into a prime (18969971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23193 + ... + 23996.

It is an arithmetic number, because the mean of its divisors is an integer number (2406690).

Almost surely, 2^18969978 is an apocalyptic number.

18969978 is an abundant number, since it is smaller than the sum of its proper divisors (19537062).

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

18969978 is a wasteful number, since it uses less digits than its factorization.

18969978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47261.

The product of its digits is 1959552, while the sum is 57.

The square root of 18969978 is about 4355.4538225081. The cubic root of 18969978 is about 266.6995455988.

The spelling of 18969978 in words is "eighteen million, nine hundred sixty-nine thousand, nine hundred seventy-eight".