201991904 has 24 divisors (see below), whose sum is σ = 405178200. Its totient is φ = 99089536.

The previous prime is 201991897. The next prime is 201992009. The reversal of 201991904 is 409199102.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57854 + ... + 61245.

It is an arithmetic number, because the mean of its divisors is an integer number (16882425).

Almost surely, 2^201991904 is an apocalyptic number.

It is an amenable number.

201991904 is an abundant number, since it is smaller than the sum of its proper divisors (203186296).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

201991904 is a wasteful number, since it uses less digits than its factorization.

201991904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119162 (or 119154 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 35.

The square root of 201991904 is about 14212.3855844119. The cubic root of 201991904 is about 586.7385919621.

The spelling of 201991904 in words is "two hundred one million, nine hundred ninety-one thousand, nine hundred four".