15542139 has 4 divisors (see below), whose sum is σ = 20722856. Its totient is φ = 10361424.

The previous prime is 15542119. The next prime is 15542143. The reversal of 15542139 is 93124551.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 15542139 - 2⁷ = 15542011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15542119) 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, 2590354 + ... + 2590359.

It is an arithmetic number, because the mean of its divisors is an integer number (5180714).

Almost surely, 2^15542139 is an apocalyptic number.

15542139 is a deficient number, since it is larger than the sum of its proper divisors (5180717).

15542139 is an equidigital number, since it uses as much as digits as its factorization.

15542139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5180716.

The product of its digits is 5400, while the sum is 30.

The square root of 15542139 is about 3942.3519629784. The cubic root of 15542139 is about 249.5572911650.

The spelling of 15542139 in words is "fifteen million, five hundred forty-two thousand, one hundred thirty-nine".