390981 has 8 divisors (see below), whose sum is σ = 531360. Its totient is φ = 255632.

The previous prime is 390967. The next prime is 390989. The reversal of 390981 is 189093.

390981 = T₉₄ + T₉₅ + ... + T₁₄₆.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 390981 - 2¹⁰ = 389957 is a prime.

It is a super-2 number, since 2×390981² = 305732284722, which contains 22 as substring.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 390981.

It is not an unprimeable number, because it can be changed into a prime (390989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1071 + ... + 1388.

It is an arithmetic number, because the mean of its divisors is an integer number (66420).

2³⁹⁰⁹⁸¹ is an apocalyptic number.

It is an amenable number.

390981 is a deficient number, since it is larger than the sum of its proper divisors (140379).

390981 is a wasteful number, since it uses less digits than its factorization.

390981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2515.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 390981 is about 625.2847351407. The cubic root of 390981 is about 73.1226436526.

The spelling of 390981 in words is "three hundred ninety thousand, nine hundred eighty-one".