1231990 has 16 divisors (see below), whose sum is σ = 2348352. Its totient is φ = 463744.

The previous prime is 1231987. The next prime is 1231999. The reversal of 1231990 is 991321.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3454 + ... + 3793.

It is an arithmetic number, because the mean of its divisors is an integer number (146772).

2^1231990 is an apocalyptic number.

1231990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1231990 is a deficient number, since it is larger than the sum of its proper divisors (1116362).

1231990 is a wasteful number, since it uses less digits than its factorization.

1231990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7271.

The product of its (nonzero) digits is 486, while the sum is 25.

The square root of 1231990 is about 1109.9504493445. The cubic root of 1231990 is about 107.2018781694.

The spelling of 1231990 in words is "one million, two hundred thirty-one thousand, nine hundred ninety".