21649708080 has 2560 divisors, whose sum is σ = 115192627200. Its totient is φ = 3583180800.

The previous prime is 21649708043. The next prime is 21649708103. The reversal of 21649708080 is 8080794612.

21649708080 is a `hidden beast` number, since 2 + 1 + 6 + 497 + 0 + 80 + 80 = 666.

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 an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 511 ways as a sum of consecutive naturals, for example, 698377665 + ... + 698377695.

It is an arithmetic number, because the mean of its divisors is an integer number (44997120).

Almost surely, 2^21649708080 is an apocalyptic number.

21649708080 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 21649708080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (57596313600).

21649708080 is an abundant number, since it is smaller than the sum of its proper divisors (93542919120).

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

21649708080 is a wasteful number, since it uses less digits than its factorization.

21649708080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The spelling of 21649708080 in words is "twenty-one billion, six hundred forty-nine million, seven hundred eight thousand, eighty".