1299521264 has 40 divisors (see below), whose sum is σ = 2657568000. Its totient is φ = 613884096.

The previous prime is 1299521263. The next prime is 1299521269. The reversal of 1299521264 is 4621259921.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1299521261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 109577 + ... + 120855.

It is an arithmetic number, because the mean of its divisors is an integer number (66439200).

Almost surely, 2^1299521264 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 1299521264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1328784000).

1299521264 is an abundant number, since it is smaller than the sum of its proper divisors (1358046736).

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

1299521264 is a wasteful number, since it uses less digits than its factorization.

1299521264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11685 (or 11679 counting only the distinct ones).

The product of its digits is 77760, while the sum is 41.

The square root of 1299521264 is about 36048.8732694935. The cubic root of 1299521264 is about 1091.2588950577.

The spelling of 1299521264 in words is "one billion, two hundred ninety-nine million, five hundred twenty-one thousand, two hundred sixty-four".