1391990 has 8 divisors (see below), whose sum is σ = 2505600. Its totient is φ = 556792.

The previous prime is 1391989. The next prime is 1392007. The reversal of 1391990 is 991931.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69590 + ... + 69609.

It is an arithmetic number, because the mean of its divisors is an integer number (313200).

2^1391990 is an apocalyptic number.

1391990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1391990 is a deficient number, since it is larger than the sum of its proper divisors (1113610).

1391990 is a wasteful number, since it uses less digits than its factorization.

1391990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139206.

The product of its (nonzero) digits is 2187, while the sum is 32.

The square root of 1391990 is about 1179.8262583957. The cubic root of 1391990 is about 111.6551360585.

The spelling of 1391990 in words is "one million, three hundred ninety-one thousand, nine hundred ninety".