1261859359664 has 20 divisors (see below), whose sum is σ = 2446009627656. Its totient is φ = 630631068672.

The previous prime is 1261859359613. The next prime is 1261859359681. The reversal of 1261859359664 is 4669539581621.

It is a super-2 number, since 2×1261859359664² (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 1261859359664.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18628334 + ... + 18695949.

Almost surely, 2^{1261859359664} is an apocalyptic number.

It is an amenable number.

1261859359664 is a deficient number, since it is larger than the sum of its proper divisors (1184150267992).

1261859359664 is a wasteful number, since it uses less digits than its factorization.

1261859359664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37326404 (or 37326398 counting only the distinct ones).

The product of its digits is 83980800, while the sum is 65.

It can be divided in two parts, 126185 and 9359664, that added together give a palindrome (9485849).

The spelling of 1261859359664 in words is "one trillion, two hundred sixty-one billion, eight hundred fifty-nine million, three hundred fifty-nine thousand, six hundred sixty-four".