393366041721 has 9 divisors (see below), whose sum is σ = 568198111429. Its totient is φ = 262242773436.

The previous prime is 393366041707. The next prime is 393366041737. The reversal of 393366041721 is 127140663393.

The square root of 393366041721 is 627189.

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

393366041721 is a `hidden beast` number, since 3 + 9 + 3 + 3 + 6 + 604 + 17 + 21 = 666.

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

It is not a de Polignac number, because 393366041721 - 2⁹ = 393366041209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (393366041021) 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, 1777036 + ... + 1986098.

Almost surely, 2^393366041721 is an apocalyptic number.

393366041721 is the 627189-th square number.

393366041721 is the 313595-th centered octagonal number.

It is an amenable number.

393366041721 is a deficient number, since it is larger than the sum of its proper divisors (174832069708).

393366041721 is an frugal number, since it uses more digits than its factorization.

393366041721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418132 (or 209066 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 45.

The spelling of 393366041721 in words is "three hundred ninety-three billion, three hundred sixty-six million, forty-one thousand, seven hundred twenty-one".