1261636608 has 88 divisors (see below), whose sum is σ = 3382790320. Its totient is φ = 418037760.

The previous prime is 1261636583. The next prime is 1261636627. The reversal of 1261636608 is 8066361621.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 554898 + ... + 557166.

Almost surely, 2^1261636608 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1261636608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1691395160).

1261636608 is an abundant number, since it is smaller than the sum of its proper divisors (2121153712).

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

1261636608 is a wasteful number, since it uses less digits than its factorization.

1261636608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2473 (or 2455 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 1261636608 is about 35519.5243211392. The cubic root of 1261636608 is about 1080.5497338484.

The spelling of 1261636608 in words is "one billion, two hundred sixty-one million, six hundred thirty-six thousand, six hundred eight".