395231621 has 2 divisors, whose sum is σ = 395231622. Its totient is φ = 395231620.

The previous prime is 395231591. The next prime is 395231647. The reversal of 395231621 is 126132593.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 388523521 + 6708100 = 19711^2 + 2590^2 .

It is a cyclic number.

It is not a de Polignac number, because 395231621 - 2²⁶ = 328122757 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (395231651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 197615810 + 197615811.

It is an arithmetic number, because the mean of its divisors is an integer number (197615811).

Almost surely, 2^395231621 is an apocalyptic number.

It is an amenable number.

395231621 is a deficient number, since it is larger than the sum of its proper divisors (1).

395231621 is an equidigital number, since it uses as much as digits as its factorization.

395231621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9720, while the sum is 32.

The square root of 395231621 is about 19880.4331190243. The cubic root of 395231621 is about 733.8667782331.

The spelling of 395231621 in words is "three hundred ninety-five million, two hundred thirty-one thousand, six hundred twenty-one".