1261637912730 has 64 divisors (see below), whose sum is σ = 3262472293248. Its totient is φ = 310402402560.

The previous prime is 1261637912729. The next prime is 1261637912747. The reversal of 1261637912730 is 372197361621.

It is a happy number.

It is a super-2 number, since 2×1261637912730² (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 1261637912730.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20029 + ... + 1588608.

It is an arithmetic number, because the mean of its divisors is an integer number (50976129582).

Almost surely, 2^{1261637912730} is an apocalyptic number.

1261637912730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1261637912730 is an abundant number, since it is smaller than the sum of its proper divisors (2000834380518).

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

1261637912730 is a wasteful number, since it uses less digits than its factorization.

1261637912730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1610671.

The product of its (nonzero) digits is 571536, while the sum is 48.

The spelling of 1261637912730 in words is "one trillion, two hundred sixty-one billion, six hundred thirty-seven million, nine hundred twelve thousand, seven hundred thirty".