18656940 has 24 divisors (see below), whose sum is σ = 52239600. Its totient is φ = 4975168.

The previous prime is 18656929. The next prime is 18656951. The reversal of 18656940 is 4965681.

It is an interprime number because it is at equal distance from previous prime (18656929) and next prime (18656951).

It is an unprimeable number.

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, 155415 + ... + 155534.

It is an arithmetic number, because the mean of its divisors is an integer number (2176650).

Almost surely, 2^18656940 is an apocalyptic number.

18656940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18656940 is an abundant number, since it is smaller than the sum of its proper divisors (33582660).

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

18656940 is a wasteful number, since it uses less digits than its factorization.

18656940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310961 (or 310959 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The square root of 18656940 is about 4319.3680093273. The cubic root of 18656940 is about 265.2243975652.

The spelling of 18656940 in words is "eighteen million, six hundred fifty-six thousand, nine hundred forty".