15642442 has 4 divisors (see below), whose sum is σ = 23463666. Its totient is φ = 7821220.

The previous prime is 15642439. The next prime is 15642449. The reversal of 15642442 is 24424651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24424651 = 197 ⋅123983.

It can be written as a sum of positive squares in only one way, i.e., 15610401 + 32041 = 3951^2 + 179^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 15642442.

It is not an unprimeable number, because it can be changed into a prime (15642449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3910609 + ... + 3910612.

Almost surely, 2^15642442 is an apocalyptic number.

15642442 is a deficient number, since it is larger than the sum of its proper divisors (7821224).

15642442 is an equidigital number, since it uses as much as digits as its factorization.

15642442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7821223.

The product of its digits is 7680, while the sum is 28.

The square root of 15642442 is about 3955.0527177270. The cubic root of 15642442 is about 250.0929894076.

The spelling of 15642442 in words is "fifteen million, six hundred forty-two thousand, four hundred forty-two".