393917261 has 2 divisors, whose sum is σ = 393917262. Its totient is φ = 393917260.

The previous prime is 393917233. The next prime is 393917269. The reversal of 393917261 is 162719393.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 382398025 + 11519236 = 19555^2 + 3394^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-393917261 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (393917269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 196958630 + 196958631.

It is an arithmetic number, because the mean of its divisors is an integer number (196958631).

Almost surely, 2^393917261 is an apocalyptic number.

It is an amenable number.

393917261 is a deficient number, since it is larger than the sum of its proper divisors (1).

393917261 is an equidigital number, since it uses as much as digits as its factorization.

393917261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 61236, while the sum is 41.

The square root of 393917261 is about 19847.3489665497. The cubic root of 393917261 is about 733.0523727877.

The spelling of 393917261 in words is "three hundred ninety-three million, nine hundred seventeen thousand, two hundred sixty-one".