390256381 has 2 divisors, whose sum is σ = 390256382. Its totient is φ = 390256380.

The previous prime is 390256379. The next prime is 390256397. The reversal of 390256381 is 183652093.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 292068100 + 98188281 = 17090^2 + 9909^2 .

It is a cyclic number.

It is not a de Polignac number, because 390256381 - 2¹ = 390256379 is a prime.

It is a super-2 number, since 2×390256381² = 304600085822434322, which contains 22 as substring.

Together with 390256379, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 390256381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (390257381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195128190 + 195128191.

It is an arithmetic number, because the mean of its divisors is an integer number (195128191).

Almost surely, 2^390256381 is an apocalyptic number.

It is an amenable number.

390256381 is a deficient number, since it is larger than the sum of its proper divisors (1).

390256381 is an equidigital number, since it uses as much as digits as its factorization.

390256381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 390256381 is about 19754.9077699695. The cubic root of 390256381 is about 730.7744211740.

The spelling of 390256381 in words is "three hundred ninety million, two hundred fifty-six thousand, three hundred eighty-one".