13978664 has 32 divisors (see below), whose sum is σ = 31259520. Its totient is φ = 5729856.

The previous prime is 13978649. The next prime is 13978669. The reversal of 13978664 is 46687931.

It is not an unprimeable number, because it can be changed into a prime (13978669) 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, 4139 + ... + 6714.

It is an arithmetic number, because the mean of its divisors is an integer number (976860).

Almost surely, 2^13978664 is an apocalyptic number.

13978664 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

13978664 is an abundant number, since it is smaller than the sum of its proper divisors (17280856).

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

13978664 is a wasteful number, since it uses less digits than its factorization.

13978664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10889 (or 10885 counting only the distinct ones).

The product of its digits is 217728, while the sum is 44.

The square root of 13978664 is about 3738.8051567312. The cubic root of 13978664 is about 240.8917289407.

The spelling of 13978664 in words is "thirteen million, nine hundred seventy-eight thousand, six hundred sixty-four".