15720013 has 4 divisors (see below), whose sum is σ = 15732000. Its totient is φ = 15708028.

The previous prime is 15719999. The next prime is 15720037. The reversal of 15720013 is 31002751.

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 a 3-Lehmer number, since φ(15720013) divides (15720013-1)³.

It is a cyclic number.

It is not a de Polignac number, because 15720013 - 2¹⁷ = 15588941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15720073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3745 + ... + 6742.

It is an arithmetic number, because the mean of its divisors is an integer number (3933000).

Almost surely, 2^15720013 is an apocalyptic number.

It is an amenable number.

15720013 is a deficient number, since it is larger than the sum of its proper divisors (11987).

15720013 is a wasteful number, since it uses less digits than its factorization.

15720013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11986.

The product of its (nonzero) digits is 210, while the sum is 19.

The square root of 15720013 is about 3964.8471597276. The cubic root of 15720013 is about 250.5057123304.

Adding to 15720013 its reverse (31002751), we get a palindrome (46722764).

The spelling of 15720013 in words is "fifteen million, seven hundred twenty thousand, thirteen".