1231780864 has 44 divisors (see below), whose sum is σ = 2474462728. Its totient is φ = 612864000.

The previous prime is 1231780831. The next prime is 1231780867. The reversal of 1231780864 is 4680871321.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231780867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 213214 + ... + 218914.

Almost surely, 2^1231780864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1231780864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1237231364).

1231780864 is an abundant number, since it is smaller than the sum of its proper divisors (1242681864).

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

1231780864 is an equidigital number, since it uses as much as digits as its factorization.

1231780864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5932 (or 5914 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 40.

The square root of 1231780864 is about 35096.7358026355. The cubic root of 1231780864 is about 1071.9581182123.

The spelling of 1231780864 in words is "one billion, two hundred thirty-one million, seven hundred eighty thousand, eight hundred sixty-four".