647781912801 has 9 divisors (see below), whose sum is σ = 935688472849. Its totient is φ = 431852998836.

The previous prime is 647781912781. The next prime is 647781912803. The reversal of 647781912801 is 108219187746.

The square root of 647781912801 is 804849.

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

647781912801 is a `hidden beast` number, since 6 + 477 + 8 + 1 + 91 + 2 + 80 + 1 = 666.

647781912801 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 647781912801 - 2¹⁵ = 647781880033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647781912803) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2280406 + ... + 2548688.

Almost surely, 2^647781912801 is an apocalyptic number.

647781912801 is the 804849-th square number.

647781912801 is the 402425-th centered octagonal number.

It is an amenable number.

647781912801 is a deficient number, since it is larger than the sum of its proper divisors (287906560048).

647781912801 is an frugal number, since it uses more digits than its factorization.

647781912801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 536572 (or 268286 counting only the distinct ones).

The product of its (nonzero) digits is 1354752, while the sum is 54.

The spelling of 647781912801 in words is "six hundred forty-seven billion, seven hundred eighty-one million, nine hundred twelve thousand, eight hundred one".