1390185887 has 4 divisors (see below), whose sum is σ = 1390809576. Its totient is φ = 1389562200.

The previous prime is 1390185883. The next prime is 1390185947. The reversal of 1390185887 is 7885810931.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1390185887 - 2² = 1390185883 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1390185883) 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, 308489 + ... + 312962.

It is an arithmetic number, because the mean of its divisors is an integer number (347702394).

Almost surely, 2^1390185887 is an apocalyptic number.

1390185887 is a deficient number, since it is larger than the sum of its proper divisors (623689).

1390185887 is an equidigital number, since it uses as much as digits as its factorization.

1390185887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 623688.

The product of its (nonzero) digits is 483840, while the sum is 50.

The square root of 1390185887 is about 37285.1966201065. The cubic root of 1390185887 is about 1116.0687767272.

The spelling of 1390185887 in words is "one billion, three hundred ninety million, one hundred eighty-five thousand, eight hundred eighty-seven".