13390721 has 8 divisors (see below), whose sum is σ = 13990080. Its totient is φ = 12800592.

The previous prime is 13390709. The next prime is 13390733. The reversal of 13390721 is 12709331.

It is an interprime number because it is at equal distance from previous prime (13390709) and next prime (13390733).

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 13390721 - 2¹⁴ = 13374337 is a prime.

It is a super-2 number, since 2×13390721² = 358622817799682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13390771) 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, 746 + ... + 5228.

It is an arithmetic number, because the mean of its divisors is an integer number (1748760).

Almost surely, 2^13390721 is an apocalyptic number.

It is an amenable number.

13390721 is a deficient number, since it is larger than the sum of its proper divisors (599359).

13390721 is a wasteful number, since it uses less digits than its factorization.

13390721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4615.

The product of its (nonzero) digits is 1134, while the sum is 26.

The square root of 13390721 is about 3659.3334092427. Note that the first 3 decimals coincide. The cubic root of 13390721 is about 237.4659363889.

The spelling of 13390721 in words is "thirteen million, three hundred ninety thousand, seven hundred twenty-one".