209678740562944 has 99 divisors (see below), whose sum is σ = 421474685057803. Its totient is φ = 104261780553728.

The previous prime is 209678740562933. The next prime is 209678740563001. The reversal of 209678740562944 is 449265047876902.

The square root of 209678740562944 is 14480288.

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

It can be written as a sum of positive squares in 4 ways, for example, as 69387034092544 + 140291706470400 = 8329888^2 + 11844480^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 91283734404 + ... + 91283736700.

Almost surely, 2^{209678740562944} is an apocalyptic number.

209678740562944 is the 14480288-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 209678740562944

209678740562944 is an abundant number, since it is smaller than the sum of its proper divisors (211795944494859).

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

209678740562944 is an frugal number, since it uses more digits than its factorization.

209678740562944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5008 (or 2496 counting only the distinct ones).

The product of its (nonzero) digits is 1463132160, while the sum is 73.

The spelling of 209678740562944 in words is "two hundred nine trillion, six hundred seventy-eight billion, seven hundred forty million, five hundred sixty-two thousand, nine hundred forty-four".