1231643880 has 320 divisors, whose sum is σ = 4469256000. Its totient is φ = 303077376.

The previous prime is 1231643879. The next prime is 1231643893. The reversal of 1231643880 is 883461321.

1231643880 is a `hidden beast` number, since 1 + 2 + 3 + 1 + 643 + 8 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 3249531 + ... + 3249909.

It is an arithmetic number, because the mean of its divisors is an integer number (13966425).

Almost surely, 2^1231643880 is an apocalyptic number.

1231643880 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 1231643880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2234628000).

1231643880 is an abundant number, since it is smaller than the sum of its proper divisors (3237612120).

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

1231643880 is a wasteful number, since it uses less digits than its factorization.

1231643880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478 (or 465 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 1231643880 is about 35094.7842278593. The cubic root of 1231643880 is about 1071.9183799334.

The spelling of 1231643880 in words is "one billion, two hundred thirty-one million, six hundred forty-three thousand, eight hundred eighty".