209420256 has 24 divisors (see below), whose sum is σ = 549728424. Its totient is φ = 69806720.

The previous prime is 209420249. The next prime is 209420257. The reversal of 209420256 is 652024902.

It is a tau number, because it is divible by the number of its divisors (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209420257) 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, 1090635 + ... + 1090826.

It is an arithmetic number, because the mean of its divisors is an integer number (22905351).

Almost surely, 2^209420256 is an apocalyptic number.

It is an amenable number.

209420256 is an abundant number, since it is smaller than the sum of its proper divisors (340308168).

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

209420256 is a wasteful number, since it uses less digits than its factorization.

209420256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2181474 (or 2181466 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 209420256 is about 14471.3598531721. The cubic root of 209420256 is about 593.8447144786.

The spelling of 209420256 in words is "two hundred nine million, four hundred twenty thousand, two hundred fifty-six".