13965821 has 4 divisors (see below), whose sum is σ = 14028672. Its totient is φ = 13902972.

The previous prime is 13965811. The next prime is 13965827. The reversal of 13965821 is 12856931.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12856931 = 23 ⋅558997.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13965821 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 (13965827) 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, 31091 + ... + 31536.

It is an arithmetic number, because the mean of its divisors is an integer number (3507168).

Almost surely, 2^13965821 is an apocalyptic number.

It is an amenable number.

13965821 is a deficient number, since it is larger than the sum of its proper divisors (62851).

13965821 is an equidigital number, since it uses as much as digits as its factorization.

13965821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62850.

The product of its digits is 12960, while the sum is 35.

The square root of 13965821 is about 3737.0872347324. The cubic root of 13965821 is about 240.8179326553.

The spelling of 13965821 in words is "thirteen million, nine hundred sixty-five thousand, eight hundred twenty-one".