13631921 has 2 divisors, whose sum is σ = 13631922. Its totient is φ = 13631920.

The previous prime is 13631899. The next prime is 13631957. The reversal of 13631921 is 12913631.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13424896 + 207025 = 3664^2 + 455^2 .

It is a cyclic number.

It is not a de Polignac number, because 13631921 - 2⁶ = 13631857 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (13631221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6815960 + 6815961.

It is an arithmetic number, because the mean of its divisors is an integer number (6815961).

Almost surely, 2^13631921 is an apocalyptic number.

It is an amenable number.

13631921 is a deficient number, since it is larger than the sum of its proper divisors (1).

13631921 is an equidigital number, since it uses as much as digits as its factorization.

13631921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 972, while the sum is 26.

The square root of 13631921 is about 3692.1431445706. The cubic root of 13631921 is about 238.8832433335.

The spelling of 13631921 in words is "thirteen million, six hundred thirty-one thousand, nine hundred twenty-one".