13978559 has 4 divisors (see below), whose sum is σ = 15975504. Its totient is φ = 11981616.

The previous prime is 13978537. The next prime is 13978567. The reversal of 13978559 is 95587931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 95587931 = 23 ⋅4155997.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13978559 is a prime.

It is a super-2 number, since 2×13978559² = 390800223432962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13978519) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 998462 + ... + 998475.

It is an arithmetic number, because the mean of its divisors is an integer number (3993876).

Almost surely, 2^13978559 is an apocalyptic number.

13978559 is a deficient number, since it is larger than the sum of its proper divisors (1996945).

13978559 is an equidigital number, since it uses as much as digits as its factorization.

13978559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1996944.

The product of its digits is 340200, while the sum is 47.

The square root of 13978559 is about 3738.7911147856. The cubic root of 13978559 is about 240.8911257907.

The spelling of 13978559 in words is "thirteen million, nine hundred seventy-eight thousand, five hundred fifty-nine".