13621973 has 4 divisors (see below), whose sum is σ = 13629708. Its totient is φ = 13614240.

The previous prime is 13621969. The next prime is 13621991. The reversal of 13621973 is 37912631.

It is a happy number.

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.

It can be written as a sum of positive squares in 2 ways, for example, as 13010449 + 611524 = 3607^2 + 782^2 .

It is a cyclic number.

It is not a de Polignac number, because 13621973 - 2² = 13621969 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13621903) 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, 203 + ... + 5223.

It is an arithmetic number, because the mean of its divisors is an integer number (3407427).

Almost surely, 2^13621973 is an apocalyptic number.

It is an amenable number.

13621973 is a deficient number, since it is larger than the sum of its proper divisors (7735).

13621973 is an equidigital number, since it uses as much as digits as its factorization.

13621973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7734.

The product of its digits is 6804, while the sum is 32.

The square root of 13621973 is about 3690.7957136639. The cubic root of 13621973 is about 238.8251202266.

The spelling of 13621973 in words is "thirteen million, six hundred twenty-one thousand, nine hundred seventy-three".