16939581 has 8 divisors (see below), whose sum is σ = 22793760. Its totient is φ = 11189232.

The previous prime is 16939579. The next prime is 16939589. The reversal of 16939581 is 18593961.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 16939581 - 2¹ = 16939579 is a prime.

It is a super-2 number, since 2×16939581² = 573898808911122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16939589) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25575 + ... + 26228.

It is an arithmetic number, because the mean of its divisors is an integer number (2849220).

Almost surely, 2^16939581 is an apocalyptic number.

It is an amenable number.

16939581 is a deficient number, since it is larger than the sum of its proper divisors (5854179).

16939581 is a wasteful number, since it uses less digits than its factorization.

16939581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51915.

The product of its digits is 58320, while the sum is 42.

The square root of 16939581 is about 4115.7722240182. The cubic root of 16939581 is about 256.8231812761.

The spelling of 16939581 in words is "sixteen million, nine hundred thirty-nine thousand, five hundred eighty-one".