1231689140 has 48 divisors (see below), whose sum is σ = 2863836864. Its totient is φ = 441196800.

The previous prime is 1231689139. The next prime is 1231689143. The reversal of 1231689140 is 419861321.

It is a self number, because there is not a number n which added to its sum of digits gives 1231689140.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231689143) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27041 + ... + 56520.

It is an arithmetic number, because the mean of its divisors is an integer number (59663268).

Almost surely, 2^1231689140 is an apocalyptic number.

1231689140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1231689140 is an abundant number, since it is smaller than the sum of its proper divisors (1632147724).

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

1231689140 is a wasteful number, since it uses less digits than its factorization.

1231689140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83648 (or 83646 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 1231689140 is about 35095.4290470996. The cubic root of 1231689140 is about 1071.9315099277.

The spelling of 1231689140 in words is "one billion, two hundred thirty-one million, six hundred eighty-nine thousand, one hundred forty".