195331721 has 24 divisors (see below), whose sum is σ = 218405376. Its totient is φ = 174545280.

The previous prime is 195331691. The next prime is 195331739. The reversal of 195331721 is 127133591.

It is a de Polignac number, because none of the positive numbers 2^k-195331721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (195337721) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 875816 + ... + 876038.

It is an arithmetic number, because the mean of its divisors is an integer number (9100224).

Almost surely, 2^195331721 is an apocalyptic number.

It is an amenable number.

195331721 is a deficient number, since it is larger than the sum of its proper divisors (23073655).

195331721 is a wasteful number, since it uses less digits than its factorization.

195331721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393 (or 380 counting only the distinct ones).

The product of its digits is 5670, while the sum is 32.

The square root of 195331721 is about 13976.1125138573. The cubic root of 195331721 is about 580.2176363195.

The spelling of 195331721 in words is "one hundred ninety-five million, three hundred thirty-one thousand, seven hundred twenty-one".