209122745656 has 32 divisors (see below), whose sum is σ = 427830666480. Its totient is φ = 95038105600.

The previous prime is 209122745617. The next prime is 209122745707. The reversal of 209122745656 is 656547221902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 260430 + ... + 697186.

Almost surely, 2^209122745656 is an apocalyptic number.

It is an amenable number.

209122745656 is an abundant number, since it is smaller than the sum of its proper divisors (218707920824).

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

209122745656 is a wasteful number, since it uses less digits than its factorization.

209122745656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442215 (or 442211 counting only the distinct ones).

The product of its (nonzero) digits is 1814400, while the sum is 49.

The spelling of 209122745656 in words is "two hundred nine billion, one hundred twenty-two million, seven hundred forty-five thousand, six hundred fifty-six".