13031921 has 8 divisors (see below), whose sum is σ = 14921664. Its totient is φ = 11149200.

The previous prime is 13031899. The next prime is 13031981. The reversal of 13031921 is 12913031.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 13031921 - 2¹⁴ = 13015537 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13031893 and 13031902.

It is not an unprimeable number, because it can be changed into a prime (13031981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3146 + ... + 5996.

It is an arithmetic number, because the mean of its divisors is an integer number (1865208).

Almost surely, 2^13031921 is an apocalyptic number.

It is an amenable number.

13031921 is a deficient number, since it is larger than the sum of its proper divisors (1889743).

13031921 is an equidigital number, since it uses as much as digits as its factorization.

13031921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3511.

The product of its (nonzero) digits is 162, while the sum is 20.

The square root of 13031921 is about 3609.9752076711. The cubic root of 13031921 is about 235.3257651954.

Adding to 13031921 its reverse (12913031), we get a palindrome (25944952).

The spelling of 13031921 in words is "thirteen million, thirty-one thousand, nine hundred twenty-one".