15720157 has 4 divisors (see below), whose sum is σ = 15824416. Its totient is φ = 15615900.

The previous prime is 15720101. The next prime is 15720167. The reversal of 15720157 is 75102751.

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, and also an emirpimes, since its reverse is a distinct semiprime: 75102751 = 23 ⋅3265337.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15720157 is a prime.

It is a super-2 number, since 2×15720157² = 494246672209298, 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 (15720167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51903 + ... + 52204.

It is an arithmetic number, because the mean of its divisors is an integer number (3956104).

Almost surely, 2^15720157 is an apocalyptic number.

It is an amenable number.

15720157 is a deficient number, since it is larger than the sum of its proper divisors (104259).

15720157 is a wasteful number, since it uses less digits than its factorization.

15720157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104258.

The product of its (nonzero) digits is 2450, while the sum is 28.

The square root of 15720157 is about 3964.8653192763. The cubic root of 15720157 is about 250.5064772303.

The spelling of 15720157 in words is "fifteen million, seven hundred twenty thousand, one hundred fifty-seven".