1261980194400 has 180 divisors, whose sum is σ = 4602196620252. Its totient is φ = 336528034560.

The previous prime is 1261980194357. The next prime is 1261980194413. The reversal of 1261980194400 is 44910891621.

It is a happy number.

1261980194400 is a `hidden beast` number, since 1 + 2 + 6 + 198 + 0 + 19 + 440 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (180).

It is a super-2 number, since 2×1261980194400² (a number of 25 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 9672702 + ... + 9802301.

Almost surely, 2^{1261980194400} is an apocalyptic number.

1261980194400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1261980194400 is an abundant number, since it is smaller than the sum of its proper divisors (3340216425852).

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

1261980194400 is a wasteful number, since it uses less digits than its factorization.

1261980194400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19475035 (or 19475013 counting only the distinct ones).

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

The spelling of 1261980194400 in words is "one trillion, two hundred sixty-one billion, nine hundred eighty million, one hundred ninety-four thousand, four hundred".