13857491 has 4 divisors (see below), whose sum is σ = 13867512. Its totient is φ = 13847472.

The previous prime is 13857461. The next prime is 13857509. The reversal of 13857491 is 19475831.

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: 19475831 = 127 ⋅153353.

It is a cyclic number.

It is not a de Polignac number, because 13857491 - 2⁶ = 13857427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13857401) 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, 2525 + ... + 5838.

It is an arithmetic number, because the mean of its divisors is an integer number (3466878).

Almost surely, 2^13857491 is an apocalyptic number.

13857491 is a deficient number, since it is larger than the sum of its proper divisors (10021).

13857491 is an equidigital number, since it uses as much as digits as its factorization.

13857491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10020.

The product of its digits is 30240, while the sum is 38.

The square root of 13857491 is about 3722.5651102432. The cubic root of 13857491 is about 240.1936573522.

The spelling of 13857491 in words is "thirteen million, eight hundred fifty-seven thousand, four hundred ninety-one".