397120861 has 2 divisors, whose sum is σ = 397120862. Its totient is φ = 397120860.

The previous prime is 397120849. The next prime is 397120903. The reversal of 397120861 is 168021793.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 253000836 + 144120025 = 15906^2 + 12005^2 .

It is a cyclic number.

It is not a de Polignac number, because 397120861 - 2¹⁹ = 396596573 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 397120861.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (397120831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198560430 + 198560431.

It is an arithmetic number, because the mean of its divisors is an integer number (198560431).

Almost surely, 2^397120861 is an apocalyptic number.

It is an amenable number.

397120861 is a deficient number, since it is larger than the sum of its proper divisors (1).

397120861 is an equidigital number, since it uses as much as digits as its factorization.

397120861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 397120861 is about 19927.8915342291. The cubic root of 397120861 is about 735.0342347575.

The spelling of 397120861 in words is "three hundred ninety-seven million, one hundred twenty thousand, eight hundred sixty-one".