13778971 has 4 divisors (see below), whose sum is σ = 14504200. Its totient is φ = 13053744.

The previous prime is 13778957. The next prime is 13778983. The reversal of 13778971 is 17987731.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17987731 = 1171 ⋅15361.

It is a cyclic number.

It is not a de Polignac number, because 13778971 - 2⁹ = 13778459 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13778951) 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, 362586 + ... + 362623.

It is an arithmetic number, because the mean of its divisors is an integer number (3626050).

Almost surely, 2^13778971 is an apocalyptic number.

13778971 is a deficient number, since it is larger than the sum of its proper divisors (725229).

13778971 is an equidigital number, since it uses as much as digits as its factorization.

13778971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 725228.

The product of its digits is 74088, while the sum is 43.

The square root of 13778971 is about 3712.0036368517. The cubic root of 13778971 is about 239.7391320617.

The spelling of 13778971 in words is "thirteen million, seven hundred seventy-eight thousand, nine hundred seventy-one".