1261757952000 has 3328 divisors, whose sum is σ = 6182488166400. Its totient is φ = 246310502400.

The previous prime is 1261757951963. The next prime is 1261757952001. The reversal of 1261757952000 is 2597571621.

1261757952000 is a `hidden beast` number, since 1 + 2 + 617 + 5 + 7 + 9 + 5 + 20 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (3328).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261757952001) by changing a digit.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 21385727971 + ... + 21385728029.

It is an arithmetic number, because the mean of its divisors is an integer number (1857718800).

Almost surely, 2^{1261757952000} is an apocalyptic number.

1261757952000 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 1261757952000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3091244083200).

1261757952000 is an abundant number, since it is smaller than the sum of its proper divisors (4920730214400).

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

1261757952000 is a wasteful number, since it uses less digits than its factorization.

1261757952000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 264600, while the sum is 45.

The spelling of 1261757952000 in words is "one trillion, two hundred sixty-one billion, seven hundred fifty-seven million, nine hundred fifty-two thousand".