390839731 has 6 divisors (see below), whose sum is σ = 392980796. Its totient is φ = 388701600.

The previous prime is 390839719. The next prime is 390839753. The reversal of 390839731 is 137938093.

It is not a de Polignac number, because 390839731 - 2¹¹ = 390837683 is a prime.

It is a super-2 number, since 2×390839731² = 305511390656304722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (390839711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 286491 + ... + 287851.

Almost surely, 2^390839731 is an apocalyptic number.

390839731 is a deficient number, since it is larger than the sum of its proper divisors (2141065).

390839731 is an frugal number, since it uses more digits than its factorization.

390839731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2933 (or 1572 counting only the distinct ones).

The product of its (nonzero) digits is 122472, while the sum is 43.

The square root of 390839731 is about 19769.6669420605. Note that the first 3 decimals coincide. The cubic root of 390839731 is about 731.1383571639.

The spelling of 390839731 in words is "three hundred ninety million, eight hundred thirty-nine thousand, seven hundred thirty-one".