390340987 has 2 divisors, whose sum is σ = 390340988. Its totient is φ = 390340986.

The previous prime is 390340967. The next prime is 390340999. The reversal of 390340987 is 789043093.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 390340987 - 2¹⁹ = 389816699 is a prime.

It is a super-2 number, since 2×390340987² = 304732172264268338, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (390340967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195170493 + 195170494.

It is an arithmetic number, because the mean of its divisors is an integer number (195170494).

Almost surely, 2^390340987 is an apocalyptic number.

390340987 is a deficient number, since it is larger than the sum of its proper divisors (1).

390340987 is an equidigital number, since it uses as much as digits as its factorization.

390340987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 163296, while the sum is 43.

The square root of 390340987 is about 19757.0490458469. The cubic root of 390340987 is about 730.8272270013.

The spelling of 390340987 in words is "three hundred ninety million, three hundred forty thousand, nine hundred eighty-seven".