1390866881 has 4 divisors (see below), whose sum is σ = 1401019332. Its totient is φ = 1380714432.

The previous prime is 1390866853. The next prime is 1390866901. The reversal of 1390866881 is 1886680931.

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: 1886680931 = 7187 ⋅262513.

It can be written as a sum of positive squares in 2 ways, for example, as 507826225 + 883040656 = 22535^2 + 29716^2 .

It is a cyclic number.

It is not a de Polignac number, because 1390866881 - 2²² = 1386672577 is a prime.

It is a super-2 number, since 2×1390866881² = 3869021361325336322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1390865881) 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, 5076020 + ... + 5076293.

It is an arithmetic number, because the mean of its divisors is an integer number (350254833).

Almost surely, 2^1390866881 is an apocalyptic number.

It is an amenable number.

1390866881 is a deficient number, since it is larger than the sum of its proper divisors (10152451).

1390866881 is a wasteful number, since it uses less digits than its factorization.

1390866881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10152450.

The product of its (nonzero) digits is 497664, while the sum is 50.

The square root of 1390866881 is about 37294.3277322437. The cubic root of 1390866881 is about 1116.2509854707.

The spelling of 1390866881 in words is "one billion, three hundred ninety million, eight hundred sixty-six thousand, eight hundred eighty-one".