390881 has 4 divisors (see below), whose sum is σ = 413892. Its totient is φ = 367872.

The previous prime is 390877. The next prime is 390883. The reversal of 390881 is 188093.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 188093 = 239 ⋅787.

It can be written as a sum of positive squares in 2 ways, for example, as 312481 + 78400 = 559^2 + 280^2 .

It is a sliding number, since 390881 = 256 + 390625 and 1/256 + 1/390625 = 0.00390881.

It is a cyclic number.

It is not a de Polignac number, because 390881 - 2² = 390877 is a prime.

It is a super-2 number, since 2×390881² = 305575912322, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (390883) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11480 + ... + 11513.

It is an arithmetic number, because the mean of its divisors is an integer number (103473).

2³⁹⁰⁸⁸¹ is an apocalyptic number.

It is an amenable number.

390881 is a deficient number, since it is larger than the sum of its proper divisors (23011).

390881 is a wasteful number, since it uses less digits than its factorization.

390881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23010.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 390881 is about 625.2047664566. The cubic root of 390881 is about 73.1164090036.

The spelling of 390881 in words is "three hundred ninety thousand, eight hundred eighty-one".