6651953280 has 640 divisors, whose sum is σ = 28364878080. Its totient is φ = 1452515328.

The previous prime is 6651953279. The next prime is 6651953291. The reversal of 6651953280 is 823591566.

6651953280 is a `hidden beast` number, since 6 + 6 + 519 + 53 + 2 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 8345842 + ... + 8346638.

It is an arithmetic number, because the mean of its divisors is an integer number (44320122).

Almost surely, 2^6651953280 is an apocalyptic number.

6651953280 is a gapful number since it is divisible by the number (60) 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 6651953280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14182439040).

6651953280 is an abundant number, since it is smaller than the sum of its proper divisors (21712924800).

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

6651953280 is a wasteful number, since it uses less digits than its factorization.

6651953280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 858 (or 837 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The square root of 6651953280 is about 81559.5076002792. The cubic root of 6651953280 is about 1880.6864552203.

The spelling of 6651953280 in words is "six billion, six hundred fifty-one million, nine hundred fifty-three thousand, two hundred eighty".