13987778 has 16 divisors (see below), whose sum is σ = 24089280. Its totient is φ = 5967216.

The previous prime is 13987777. The next prime is 13987783. The reversal of 13987778 is 87778931.

It is not an unprimeable number, because it can be changed into a prime (13987777) 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, 1025 + ... + 5387.

It is an arithmetic number, because the mean of its divisors is an integer number (1505580).

Almost surely, 2^13987778 is an apocalyptic number.

13987778 is a deficient number, since it is larger than the sum of its proper divisors (10101502).

13987778 is a wasteful number, since it uses less digits than its factorization.

13987778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4601.

The product of its digits is 592704, while the sum is 50.

The square root of 13987778 is about 3740.0237967157. The cubic root of 13987778 is about 240.9440708584.

The spelling of 13987778 in words is "thirteen million, nine hundred eighty-seven thousand, seven hundred seventy-eight".