209902144 has 21 divisors (see below), whose sum is σ = 416754691. Its totient is φ = 104893120.

The previous prime is 209902129. The next prime is 209902153. The reversal of 209902144 is 441209902.

It is a happy number.

The square root of 209902144 is 14488.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 114999 + ... + 116809.

Almost surely, 2^209902144 is an apocalyptic number.

209902144 is the 14488-th square number.

It is an amenable number.

209902144 is a deficient number, since it is larger than the sum of its proper divisors (206852547).

209902144 is an frugal number, since it uses more digits than its factorization.

209902144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3634 (or 1813 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

The cubic root of 209902144 is about 594.2998557849.

Multiplying 209902144 by its product of nonzero digits (5184), we get a square (1088132714496 = 1043136²).

The spelling of 209902144 in words is "two hundred nine million, nine hundred two thousand, one hundred forty-four".