1391999894 has 8 divisors (see below), whose sum is σ = 2096125128. Its totient is φ = 693291520.

The previous prime is 1391999863. The next prime is 1391999911. The reversal of 1391999894 is 4989991931.

It is a happy number.

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

It is a super-2 number, since 2×1391999894² = 3875327409792022472, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1353572 + ... + 1354599.

It is an arithmetic number, because the mean of its divisors is an integer number (262015641).

Almost surely, 2^1391999894 is an apocalyptic number.

1391999894 is a deficient number, since it is larger than the sum of its proper divisors (704125234).

1391999894 is a wasteful number, since it uses less digits than its factorization.

1391999894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2708430.

The product of its digits is 5668704, while the sum is 62.

The square root of 1391999894 is about 37309.5147918061. The cubic root of 1391999894 is about 1116.5540059900.

The spelling of 1391999894 in words is "one billion, three hundred ninety-one million, nine hundred ninety-nine thousand, eight hundred ninety-four".