1231155520000 has 200 divisors, whose sum is σ = 3513033919296. Its totient is φ = 422109696000.

The previous prime is 1231155519991. The next prime is 1231155520037. The reversal of 1231155520000 is 255511321.

It is a tau number, because it is divible by the number of its divisors (200).

It is a Harshad number since it is a multiple of its sum of digits (25).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1965189 + ... + 2514811.

Almost surely, 2^{1231155520000} is an apocalyptic number.

1231155520000 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 1231155520000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1756516959648).

1231155520000 is an abundant number, since it is smaller than the sum of its proper divisors (2281878399296).

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

1231155520000 is an frugal number, since it uses more digits than its factorization.

1231155520000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 549668 (or 549637 counting only the distinct ones).

The product of its (nonzero) digits is 1500, while the sum is 25.

The spelling of 1231155520000 in words is "one trillion, two hundred thirty-one billion, one hundred fifty-five million, five hundred twenty thousand".