1261591036400 has 30 divisors (see below), whose sum is σ = 3030972465912. Its totient is φ = 504636414400.

The previous prime is 1261591036397. The next prime is 1261591036411. The reversal of 1261591036400 is 46301951621.

It is a super-2 number, since 2×1261591036400² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1576988396 + ... + 1576989195.

Almost surely, 2^{1261591036400} is an apocalyptic number.

1261591036400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1261591036400 is an abundant number, since it is smaller than the sum of its proper divisors (1769381429512).

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

1261591036400 is a wasteful number, since it uses less digits than its factorization.

1261591036400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3153977609 (or 3153977598 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 38.

The spelling of 1261591036400 in words is "one trillion, two hundred sixty-one billion, five hundred ninety-one million, thirty-six thousand, four hundred".