397835621 has 2 divisors, whose sum is σ = 397835622. Its totient is φ = 397835620.

The previous prime is 397835593. The next prime is 397835639. The reversal of 397835621 is 126538793.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 359519521 + 38316100 = 18961^2 + 6190^2 .

It is an emirp because it is prime and its reverse (126538793) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 397835621 - 2¹⁴ = 397819237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (397835651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198917810 + 198917811.

It is an arithmetic number, because the mean of its divisors is an integer number (198917811).

Almost surely, 2^397835621 is an apocalyptic number.

It is an amenable number.

397835621 is a deficient number, since it is larger than the sum of its proper divisors (1).

397835621 is an equidigital number, since it uses as much as digits as its factorization.

397835621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 272160, while the sum is 44.

The square root of 397835621 is about 19945.8171304161. The cubic root of 397835621 is about 735.4749554864.

The spelling of 397835621 in words is "three hundred ninety-seven million, eight hundred thirty-five thousand, six hundred twenty-one".