1261631310440 has 32 divisors (see below), whose sum is σ = 2838895161480. Its totient is φ = 504612575232.

The previous prime is 1261631310427. The next prime is 1261631310481. The reversal of 1261631310440 is 440131361621.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 484084760644 + 777546549796 = 695762^2 + 881786^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1261631310397 and 1261631310406.

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 7 ways as a sum of consecutive naturals, for example, 734177 + ... + 1749936.

Almost surely, 2^{1261631310440} is an apocalyptic number.

1261631310440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1261631310440 is an abundant number, since it is smaller than the sum of its proper divisors (1577263851040).

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

1261631310440 is a wasteful number, since it uses less digits than its factorization.

1261631310440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2496821 (or 2496817 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 32.

The spelling of 1261631310440 in words is "one trillion, two hundred sixty-one billion, six hundred thirty-one million, three hundred ten thousand, four hundred forty".