394775969321 has 2 divisors, whose sum is σ = 394775969322. Its totient is φ = 394775969320.

The previous prime is 394775969281. The next prime is 394775969347. The reversal of 394775969321 is 123969577493.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 258272322025 + 136503647296 = 508205^2 + 369464^2 .

It is a cyclic number.

It is not a de Polignac number, because 394775969321 - 2³⁴ = 377596100137 is a prime.

It is not a weakly prime, because it can be changed into another prime (394775969221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 197387984660 + 197387984661.

It is an arithmetic number, because the mean of its divisors is an integer number (197387984661).

Almost surely, 2^394775969321 is an apocalyptic number.

It is an amenable number.

394775969321 is a deficient number, since it is larger than the sum of its proper divisors (1).

394775969321 is an equidigital number, since it uses as much as digits as its factorization.

394775969321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77157360, while the sum is 65.

The spelling of 394775969321 in words is "three hundred ninety-four billion, seven hundred seventy-five million, nine hundred sixty-nine thousand, three hundred twenty-one".