1231980 has 24 divisors (see below), whose sum is σ = 3449712. Its totient is φ = 328512.

The previous prime is 1231961. The next prime is 1231981. The reversal of 1231980 is 891321.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 1231980.

It is not an unprimeable number, because it can be changed into a prime (1231981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10207 + ... + 10326.

It is an arithmetic number, because the mean of its divisors is an integer number (143738).

2^1231980 is an apocalyptic number.

1231980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1231980 is an abundant number, since it is smaller than the sum of its proper divisors (2217732).

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

1231980 is a wasteful number, since it uses less digits than its factorization.

1231980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20545 (or 20543 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 1231980 is about 1109.9459446297. The cubic root of 1231980 is about 107.2015881179.

It can be divided in two parts, 1231 and 980, that added together give a triangular number (2211 = T₆₆).

The spelling of 1231980 in words is "one million, two hundred thirty-one thousand, nine hundred eighty".