217972270765456 has 135 divisors (see below), whose sum is σ = 443696045087659. Its totient is φ = 103727269429696.

The previous prime is 217972270765429. The next prime is 217972270765541. The reversal of 217972270765456 is 654567072279712.

The square root of 217972270765456 is 14763884.

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

217972270765456 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 520220216415 + ... + 520220216833.

Almost surely, 2^{217972270765456} is an apocalyptic number.

217972270765456 is the 14763884-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 217972270765456

217972270765456 is an abundant number, since it is smaller than the sum of its proper divisors (225723774322203).

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

217972270765456 is an frugal number, since it uses more digits than its factorization.

217972270765456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1658 (or 827 counting only the distinct ones).

The product of its (nonzero) digits is 622339200, while the sum is 70.

The spelling of 217972270765456 in words is "two hundred seventeen trillion, nine hundred seventy-two billion, two hundred seventy million, seven hundred sixty-five thousand, four hundred fifty-six".