1261683171840 has 960 divisors, whose sum is σ = 5273046003456. Its totient is φ = 254604607488.

The previous prime is 1261683171829. The next prime is 1261683171877. The reversal of 1261683171840 is 481713861621.

It is a tau number, because it is divible by the number of its divisors (960).

It is a super-2 number, since 2×1261683171840² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 1261683171840.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 112514074 + ... + 112525286.

Almost surely, 2^{1261683171840} is an apocalyptic number.

1261683171840 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 1261683171840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2636523001728).

1261683171840 is an abundant number, since it is smaller than the sum of its proper divisors (4011362831616).

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

1261683171840 is a wasteful number, since it uses less digits than its factorization.

1261683171840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11289 (or 11266 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 48.

The spelling of 1261683171840 in words is "one trillion, two hundred sixty-one billion, six hundred eighty-three million, one hundred seventy-one thousand, eight hundred forty".