1290261636 has 180 divisors, whose sum is σ = 3642614976. Its totient is φ = 397457280.

The previous prime is 1290261617. The next prime is 1290261653. The reversal of 1290261636 is 6361620921.

It is a happy number.

1290261636 is a `hidden beast` number, since 1 + 2 + 9 + 0 + 2 + 616 + 36 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 1290261636.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 12526761 + ... + 12526863.

Almost surely, 2^1290261636 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 1290261636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1821307488).

1290261636 is an abundant number, since it is smaller than the sum of its proper divisors (2352353340).

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

1290261636 is a wasteful number, since it uses less digits than its factorization.

1290261636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224 (or 172 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 1290261636 is about 35920.2120817792. The cubic root of 1290261636 is about 1088.6608237259.

The spelling of 1290261636 in words is "one billion, two hundred ninety million, two hundred sixty-one thousand, six hundred thirty-six".