1231656578400 has 144 divisors (see below), whose sum is σ = 4059790156800. Its totient is φ = 324284213760.

The previous prime is 1231656578387. The next prime is 1231656578429. The reversal of 1231656578400 is 48756561321.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 1231656578400.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3058440 + ... + 3437639.

It is an arithmetic number, because the mean of its divisors is an integer number (28192987200).

Almost surely, 2^{1231656578400} is an apocalyptic number.

1231656578400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1231656578400 is an abundant number, since it is smaller than the sum of its proper divisors (2828133578400).

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

1231656578400 is a wasteful number, since it uses less digits than its factorization.

1231656578400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6496181 (or 6496168 counting only the distinct ones).

The product of its (nonzero) digits is 1209600, while the sum is 48.

The spelling of 1231656578400 in words is "one trillion, two hundred thirty-one billion, six hundred fifty-six million, five hundred seventy-eight thousand, four hundred".