1299267840 has 288 divisors, whose sum is σ = 4734688896. Its totient is φ = 300810240.

The previous prime is 1299267821. The next prime is 1299267841. The reversal of 1299267840 is 487629921.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 1299267840.

It is not an unprimeable number, because it can be changed into a prime (1299267841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 847875 + ... + 849405.

It is an arithmetic number, because the mean of its divisors is an integer number (16439892).

Almost surely, 2^1299267840 is an apocalyptic number.

1299267840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1299267840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2367344448).

1299267840 is an abundant number, since it is smaller than the sum of its proper divisors (3435421056).

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

1299267840 is a wasteful number, since it uses less digits than its factorization.

1299267840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1585 (or 1571 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 48.

The square root of 1299267840 is about 36045.3580922704. The cubic root of 1299267840 is about 1091.1879537603.

The spelling of 1299267840 in words is "one billion, two hundred ninety-nine million, two hundred sixty-seven thousand, eight hundred forty".