12155972400 has 960 divisors, whose sum is σ = 53936547840. Its totient is φ = 2554675200.

The previous prime is 12155972393. The next prime is 12155972407. The reversal of 12155972400 is 427955121.

12155972400 is a `hidden beast` number, since 1 + 21 + 5 + 597 + 2 + 40 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (12155972393) and next prime (12155972407).

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

It is not an unprimeable number, because it can be changed into a prime (12155972407) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 26254569 + ... + 26255031.

It is an arithmetic number, because the mean of its divisors is an integer number (56183904).

Almost surely, 2^12155972400 is an apocalyptic number.

12155972400 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 12155972400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26968273920).

12155972400 is an abundant number, since it is smaller than the sum of its proper divisors (41780575440).

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

12155972400 is a wasteful number, since it uses less digits than its factorization.

12155972400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 531 (or 514 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 36.

The spelling of 12155972400 in words is "twelve billion, one hundred fifty-five million, nine hundred seventy-two thousand, four hundred".