16939381 has 4 divisors (see below), whose sum is σ = 17000812. Its totient is φ = 16877952.

The previous prime is 16939367. The next prime is 16939399. The reversal of 16939381 is 18393961.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11222500 + 5716881 = 3350^2 + 2391^2 .

It is a cyclic number.

It is not a de Polignac number, because 16939381 - 2⁷ = 16939253 is a prime.

It is a super-2 number, since 2×16939381² = 573885257326322, 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 (16939301) 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, 30300 + ... + 30853.

It is an arithmetic number, because the mean of its divisors is an integer number (4250203).

Almost surely, 2^16939381 is an apocalyptic number.

It is an amenable number.

16939381 is a deficient number, since it is larger than the sum of its proper divisors (61431).

16939381 is an equidigital number, since it uses as much as digits as its factorization.

16939381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61430.

The product of its digits is 34992, while the sum is 40.

The square root of 16939381 is about 4115.7479271695. The cubic root of 16939381 is about 256.8221705302.

The spelling of 16939381 in words is "sixteen million, nine hundred thirty-nine thousand, three hundred eighty-one".