28296656640 has 720 divisors, whose sum is σ = 117006016512. Its totient is φ = 6395977728.

The previous prime is 28296656579. The next prime is 28296656657. The reversal of 28296656640 is 4665669282.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 92171367 + ... + 92171673.

Almost surely, 2^28296656640 is an apocalyptic number.

28296656640 is a gapful number since it is divisible by the number (20) 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 28296656640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (58503008256).

28296656640 is an abundant number, since it is smaller than the sum of its proper divisors (88709359872).

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

28296656640 is a wasteful number, since it uses less digits than its factorization.

28296656640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 474 (or 451 counting only the distinct ones).

The product of its (nonzero) digits is 7464960, while the sum is 54.

The spelling of 28296656640 in words is "twenty-eight billion, two hundred ninety-six million, six hundred fifty-six thousand, six hundred forty".