393316712725021 has 4 divisors (see below), whose sum is σ = 394043730678844. Its totient is φ = 392589694771200.

The previous prime is 393316712724961. The next prime is 393316712725039. The reversal of 393316712725021 is 120527217613393.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 225033421240996 + 168283291484025 = 15001114^2 + 12972405^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-393316712725021 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 393316712725021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (393316712725621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 363508976100 + ... + 363508977181.

It is an arithmetic number, because the mean of its divisors is an integer number (98510932669711).

Almost surely, 2^{393316712725021} is an apocalyptic number.

It is an amenable number.

393316712725021 is a deficient number, since it is larger than the sum of its proper divisors (727017953823).

393316712725021 is an equidigital number, since it uses as much as digits as its factorization.

393316712725021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 727017953822.

The product of its (nonzero) digits is 2857680, while the sum is 52.

The spelling of 393316712725021 in words is "three hundred ninety-three trillion, three hundred sixteen billion, seven hundred twelve million, seven hundred twenty-five thousand, twenty-one".