1261972800 has 504 divisors, whose sum is σ = 5070604032. Its totient is φ = 294912000.

The previous prime is 1261972783. The next prime is 1261972807. The reversal of 1261972800 is 82791621.

1261972800 is a `hidden beast` number, since 12 + 619 + 7 + 28 + 0 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261972807) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 4910272 + ... + 4910528.

Almost surely, 2^1261972800 is an apocalyptic number.

1261972800 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 1261972800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2535302016).

1261972800 is an abundant number, since it is smaller than the sum of its proper divisors (3808631232).

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

1261972800 is a wasteful number, since it uses less digits than its factorization.

1261972800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327 (or 309 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 1261972800 is about 35524.2565017201. The cubic root of 1261972800 is about 1080.6457044079.

The spelling of 1261972800 in words is "one billion, two hundred sixty-one million, nine hundred seventy-two thousand, eight hundred".