12961166400 has 1260 divisors, whose sum is σ = 60063517668. Its totient is φ = 2717245440.

The previous prime is 12961166327. The next prime is 12961166411. The reversal of 12961166400 is 466116921.

12961166400 is a `hidden beast` number, since 1 + 2 + 9 + 6 + 1 + 1 + 6 + 640 + 0 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 2390036544 + 10571129856 = 48888^2 + 102816^2 .

It is a tau number, because it is divible by the number of its divisors (1260).

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 179 ways as a sum of consecutive naturals, for example, 82555122 + ... + 82555278.

Almost surely, 2^12961166400 is an apocalyptic number.

12961166400 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 12961166400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30031758834).

12961166400 is an abundant number, since it is smaller than the sum of its proper divisors (47102351268).

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

12961166400 is a wasteful number, since it uses less digits than its factorization.

12961166400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218 (or 187 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

It can be divided in two parts, 1296 and 1166400, that multiplied together give a square (1511654400 = 38880²).

The spelling of 12961166400 in words is "twelve billion, nine hundred sixty-one million, one hundred sixty-six thousand, four hundred".