13978477 has 4 divisors (see below), whose sum is σ = 13986396. Its totient is φ = 13970560.

The previous prime is 13978469. The next prime is 13978519. The reversal of 13978477 is 77487931.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 77487931 = 2969 ⋅26099.

It can be written as a sum of positive squares in 2 ways, for example, as 9771876 + 4206601 = 3126^2 + 2051^2 .

It is a cyclic number.

It is not a de Polignac number, because 13978477 - 2³ = 13978469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13918477) 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, 27 + ... + 5287.

It is an arithmetic number, because the mean of its divisors is an integer number (3496599).

Almost surely, 2^13978477 is an apocalyptic number.

It is an amenable number.

13978477 is a deficient number, since it is larger than the sum of its proper divisors (7919).

13978477 is an equidigital number, since it uses as much as digits as its factorization.

13978477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7918.

The product of its digits is 296352, while the sum is 46.

The square root of 13978477 is about 3738.7801486581. The cubic root of 13978477 is about 240.8906547571.

The spelling of 13978477 in words is "thirteen million, nine hundred seventy-eight thousand, four hundred seventy-seven".