1261211725944 has 96 divisors (see below), whose sum is σ = 3526318448640. Its totient is φ = 406802088000.

The previous prime is 1261211725931. The next prime is 1261211725951. The reversal of 1261211725944 is 4495271121621.

It is a happy number.

1261211725944 is a `hidden beast` number, since 1 + 2 + 612 + 1 + 1 + 7 + 25 + 9 + 4 + 4 = 666.

It is a super-2 number, since 2×1261211725944² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1261211725944.

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, 29331549 + ... + 29374515.

It is an arithmetic number, because the mean of its divisors is an integer number (36732483840).

Almost surely, 2^{1261211725944} is an apocalyptic number.

It is an amenable number.

1261211725944 is an abundant number, since it is smaller than the sum of its proper divisors (2265106722696).

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

1261211725944 is a wasteful number, since it uses less digits than its factorization.

1261211725944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56161 (or 56154 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The spelling of 1261211725944 in words is "one trillion, two hundred sixty-one billion, two hundred eleven million, seven hundred twenty-five thousand, nine hundred forty-four".