1231625990 has 64 divisors (see below), whose sum is σ = 2589262848. Its totient is φ = 413078400.

The previous prime is 1231625981. The next prime is 1231626059. The reversal of 1231625990 is 995261321.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 900287 + ... + 901653.

It is an arithmetic number, because the mean of its divisors is an integer number (40457232).

Almost surely, 2^1231625990 is an apocalyptic number.

1231625990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1231625990 is an abundant number, since it is smaller than the sum of its proper divisors (1357636858).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1231625990 is a wasteful number, since it uses less digits than its factorization.

1231625990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1653.

The product of its (nonzero) digits is 29160, while the sum is 38.

The square root of 1231625990 is about 35094.5293457542. The cubic root of 1231625990 is about 1071.9131899287.

The spelling of 1231625990 in words is "one billion, two hundred thirty-one million, six hundred twenty-five thousand, nine hundred ninety".