1247009280 has 320 divisors, whose sum is σ = 4507747200. Its totient is φ = 291307520.

The previous prime is 1247009263. The next prime is 1247009303. The reversal of 1247009280 is 829007421.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (320).

It is a super-2 number, since 2×1247009280² = 3110064288812236800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2449666 + ... + 2450174.

It is an arithmetic number, because the mean of its divisors is an integer number (14086710).

Almost surely, 2^1247009280 is an apocalyptic number.

1247009280 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 1247009280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2253873600).

1247009280 is an abundant number, since it is smaller than the sum of its proper divisors (3260737920).

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

1247009280 is a wasteful number, since it uses less digits than its factorization.

1247009280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 575 (or 559 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 1247009280 is about 35313.0185625641. The cubic root of 1247009280 is about 1076.3575508211.

The spelling of 1247009280 in words is "one billion, two hundred forty-seven million, nine thousand, two hundred eighty".