393983987 has 2 divisors, whose sum is σ = 393983988. Its totient is φ = 393983986.

The previous prime is 393983977. The next prime is 393983999. The reversal of 393983987 is 789389393.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 393983987 - 2²⁸ = 125548531 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (393983917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 196991993 + 196991994.

It is an arithmetic number, because the mean of its divisors is an integer number (196991994).

Almost surely, 2^393983987 is an apocalyptic number.

393983987 is a deficient number, since it is larger than the sum of its proper divisors (1).

393983987 is an equidigital number, since it uses as much as digits as its factorization.

393983987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8817984, while the sum is 59.

The square root of 393983987 is about 19849.0298755380. The cubic root of 393983987 is about 733.0937612516.

The spelling of 393983987 in words is "three hundred ninety-three million, nine hundred eighty-three thousand, nine hundred eighty-seven".