16591961 has 4 divisors (see below), whose sum is σ = 16753152. Its totient is φ = 16430772.

The previous prime is 16591957. The next prime is 16591999. The reversal of 16591961 is 16919561.

It is a happy number.

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: 16919561 = 53 ⋅319237.

It is a cyclic number.

It is not a de Polignac number, because 16591961 - 2² = 16591957 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16591061) 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, 80441 + ... + 80646.

It is an arithmetic number, because the mean of its divisors is an integer number (4188288).

Almost surely, 2^16591961 is an apocalyptic number.

It is an amenable number.

16591961 is a deficient number, since it is larger than the sum of its proper divisors (161191).

16591961 is a wasteful number, since it uses less digits than its factorization.

16591961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161190.

The product of its digits is 14580, while the sum is 38.

The square root of 16591961 is about 4073.3230905490. The cubic root of 16591961 is about 255.0542547636.

The spelling of 16591961 in words is "sixteen million, five hundred ninety-one thousand, nine hundred sixty-one".