13201581 has 4 divisors (see below), whose sum is σ = 17602112. Its totient is φ = 8801052.

The previous prime is 13201579. The next prime is 13201633. The reversal of 13201581 is 18510231.

13201581 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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.

It is not a de Polignac number, because 13201581 - 2¹ = 13201579 is a prime.

It is a super-2 number, since 2×13201581² = 348563481799122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13201511) 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, 2200261 + ... + 2200266.

It is an arithmetic number, because the mean of its divisors is an integer number (4400528).

Almost surely, 2^13201581 is an apocalyptic number.

It is an amenable number.

13201581 is a deficient number, since it is larger than the sum of its proper divisors (4400531).

13201581 is an equidigital number, since it uses as much as digits as its factorization.

13201581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4400530.

The product of its (nonzero) digits is 240, while the sum is 21.

The square root of 13201581 is about 3633.3979963665. The cubic root of 13201581 is about 236.3425851388.

The spelling of 13201581 in words is "thirteen million, two hundred one thousand, five hundred eighty-one".