1231061780 has 96 divisors (see below), whose sum is σ = 2900161824. Its totient is φ = 435953664.

The previous prime is 1231061771. The next prime is 1231061807. The reversal of 1231061780 is 871601321.

It can be written as a sum of positive squares in 16 ways, for example, as 517744516 + 713317264 = 22754^2 + 26708^2 .

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, 701384 + ... + 703136.

It is an arithmetic number, because the mean of its divisors is an integer number (30210019).

Almost surely, 2^1231061780 is an apocalyptic number.

1231061780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1231061780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1450080912).

1231061780 is an abundant number, since it is smaller than the sum of its proper divisors (1669100044).

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

1231061780 is a wasteful number, since it uses less digits than its factorization.

1231061780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1885 (or 1883 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 29.

The square root of 1231061780 is about 35086.4899925883. The cubic root of 1231061780 is about 1071.7494831648.

The spelling of 1231061780 in words is "one billion, two hundred thirty-one million, sixty-one thousand, seven hundred eighty".