16161391 has 4 divisors (see below), whose sum is σ = 16277800. Its totient is φ = 16044984.

The previous prime is 16161389. The next prime is 16161403. The reversal of 16161391 is 19316161.

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

It is a cyclic number.

It is not a de Polignac number, because 16161391 - 2¹ = 16161389 is a prime.

It is a super-2 number, since 2×16161391² = 522381118109762, 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 (16161311) 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, 57996 + ... + 58273.

It is an arithmetic number, because the mean of its divisors is an integer number (4069450).

Almost surely, 2^16161391 is an apocalyptic number.

16161391 is a deficient number, since it is larger than the sum of its proper divisors (116409).

16161391 is a wasteful number, since it uses less digits than its factorization.

16161391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116408.

The product of its digits is 972, while the sum is 28.

The square root of 16161391 is about 4020.1232568169. The cubic root of 16161391 is about 252.8286267771.

The spelling of 16161391 in words is "sixteen million, one hundred sixty-one thousand, three hundred ninety-one".