18971690 has 32 divisors (see below), whose sum is σ = 37117440. Its totient is φ = 6955200.

The previous prime is 18971681. The next prime is 18971717. The reversal of 18971690 is 9617981.

It is a happy number.

It is a super-2 number, since 2×18971690² = 719850042912200, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4280 + ... + 7500.

It is an arithmetic number, because the mean of its divisors is an integer number (1159920).

Almost surely, 2^18971690 is an apocalyptic number.

18971690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18971690 is a deficient number, since it is larger than the sum of its proper divisors (18145750).

18971690 is a wasteful number, since it uses less digits than its factorization.

18971690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3278.

The product of its (nonzero) digits is 27216, while the sum is 41.

The square root of 18971690 is about 4355.6503532768. The cubic root of 18971690 is about 266.7075683789.

The spelling of 18971690 in words is "eighteen million, nine hundred seventy-one thousand, six hundred ninety".