16139021 has 4 divisors (see below), whose sum is σ = 16161600. Its totient is φ = 16116444.

The previous prime is 16138987. The next prime is 16139023. The reversal of 16139021 is 12093161.

It is a happy number.

16139021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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: 12093161 = 239 ⋅50599.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16139021 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 (16139023) 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, 10181 + ... + 11658.

It is an arithmetic number, because the mean of its divisors is an integer number (4040400).

Almost surely, 2^16139021 is an apocalyptic number.

It is an amenable number.

16139021 is a deficient number, since it is larger than the sum of its proper divisors (22579).

16139021 is an equidigital number, since it uses as much as digits as its factorization.

16139021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22578.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 16139021 is about 4017.3400403750. The cubic root of 16139021 is about 252.7119209008.

The spelling of 16139021 in words is "sixteen million, one hundred thirty-nine thousand, twenty-one".