1231956215808 has 384 divisors, whose sum is σ = 3516851520000. Its totient is φ = 382393516032.

The previous prime is 1231956215801. The next prime is 1231956215881. The reversal of 1231956215808 is 8085126591321.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×1231956215808² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1231956215801) 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 31 ways as a sum of consecutive naturals, for example, 2940229423 + ... + 2940229841.

It is an arithmetic number, because the mean of its divisors is an integer number (9158467500).

Almost surely, 2^{1231956215808} 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 1231956215808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1758425760000).

1231956215808 is an abundant number, since it is smaller than the sum of its proper divisors (2284895304192).

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

1231956215808 is a wasteful number, since it uses less digits than its factorization.

1231956215808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 835 (or 815 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 51.

The spelling of 1231956215808 in words is "one trillion, two hundred thirty-one billion, nine hundred fifty-six million, two hundred fifteen thousand, eight hundred eight".