1261981622016 has 108 divisors (see below), whose sum is σ = 3651024526968. Its totient is φ = 419224614912.

The previous prime is 1261981621997. The next prime is 1261981622017. The reversal of 1261981622016 is 6102261891621.

1261981622016 is a `hidden beast` number, since 1 + 2 + 6 + 1 + 9 + 8 + 1 + 622 + 0 + 16 = 666.

It is a super-2 number, since 2×1261981622016² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261981622017) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 259630 + ... + 1609773.

Almost surely, 2^{1261981622016} is an apocalyptic number.

1261981622016 is a gapful number since it is divisible by the number (16) 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 1261981622016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1825512263484).

1261981622016 is an abundant number, since it is smaller than the sum of its proper divisors (2389042904952).

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

1261981622016 is a wasteful number, since it uses less digits than its factorization.

1261981622016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1869718 (or 1869701 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The spelling of 1261981622016 in words is "one trillion, two hundred sixty-one billion, nine hundred eighty-one million, six hundred twenty-two thousand, sixteen".