15720427 has 4 divisors (see below), whose sum is σ = 16645176. Its totient is φ = 14795680.

The previous prime is 15720421. The next prime is 15720437. The reversal of 15720427 is 72402751.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 72402751 = 211 ⋅343141.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15720427 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 15720395 and 15720404.

It is not an unprimeable number, because it can be changed into a prime (15720421) 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, 462349 + ... + 462382.

It is an arithmetic number, because the mean of its divisors is an integer number (4161294).

Almost surely, 2^15720427 is an apocalyptic number.

15720427 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

15720427 is a deficient number, since it is larger than the sum of its proper divisors (924749).

15720427 is an equidigital number, since it uses as much as digits as its factorization.

15720427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 924748.

The product of its (nonzero) digits is 3920, while the sum is 28.

The square root of 15720427 is about 3964.8993682060. The cubic root of 15720427 is about 250.5079114052.

The spelling of 15720427 in words is "fifteen million, seven hundred twenty thousand, four hundred twenty-seven".