1391690 has 8 divisors (see below), whose sum is σ = 2505060. Its totient is φ = 556672.

The previous prime is 1391669. The next prime is 1391701. The reversal of 1391690 is 961931.

It can be written as a sum of positive squares in 2 ways, for example, as 1371241 + 20449 = 1171^2 + 143^2 .

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

It is a super-2 number, since 2×1391690² = 3873602112200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69575 + ... + 69594.

2^1391690 is an apocalyptic number.

1391690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1391690 is a deficient number, since it is larger than the sum of its proper divisors (1113370).

1391690 is a wasteful number, since it uses less digits than its factorization.

1391690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139176.

The product of its (nonzero) digits is 1458, while the sum is 29.

The square root of 1391690 is about 1179.6991141812. The cubic root of 1391690 is about 111.6471142222.

The spelling of 1391690 in words is "one million, three hundred ninety-one thousand, six hundred ninety".