13720978 has 8 divisors (see below), whose sum is σ = 21083580. Its totient is φ = 6693120.

The previous prime is 13720933. The next prime is 13721033. The reversal of 13720978 is 87902731.

13720978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 11202409 + 2518569 = 3347^2 + 1587^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83583 + ... + 83746.

Almost surely, 2^13720978 is an apocalyptic number.

13720978 is a deficient number, since it is larger than the sum of its proper divisors (7362602).

13720978 is a wasteful number, since it uses less digits than its factorization.

13720978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167372.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 13720978 is about 3704.1838507288. The cubic root of 13720978 is about 239.4023206869.

Subtracting from 13720978 its sum of digits (37), we obtain a triangular number (13720941 = T₅₂₃₈).

It can be divided in two parts, 137 and 20978, that added together give a triangular number (21115 = T₂₀₅).

The spelling of 13720978 in words is "thirteen million, seven hundred twenty thousand, nine hundred seventy-eight".