204651391 has 12 divisors (see below), whose sum is σ = 242558712. Its totient is φ = 172103568.

The previous prime is 204651383. The next prime is 204651407. The reversal of 204651391 is 193156402.

It is not a de Polignac number, because 204651391 - 2³ = 204651383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204651331) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 36805 + ... + 41998.

It is an arithmetic number, because the mean of its divisors is an integer number (20213226).

Almost surely, 2^204651391 is an apocalyptic number.

204651391 is a deficient number, since it is larger than the sum of its proper divisors (37907321).

204651391 is an equidigital number, since it uses as much as digits as its factorization.

204651391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78870 (or 78863 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 204651391 is about 14305.6419289733. The cubic root of 204651391 is about 589.3024323051.

The spelling of 204651391 in words is "two hundred four million, six hundred fifty-one thousand, three hundred ninety-one".