21769164720 has 280 divisors, whose sum is σ = 78339664512. Its totient is φ = 5617382400.

The previous prime is 21769164667. The next prime is 21769164757. The reversal of 21769164720 is 2746196712.

21769164720 is a `hidden beast` number, since 2 + 176 + 9 + 1 + 6 + 472 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 1801900 + ... + 1813940.

Almost surely, 2^21769164720 is an apocalyptic number.

21769164720 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 21769164720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39169832256).

21769164720 is an abundant number, since it is smaller than the sum of its proper divisors (56570499792).

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

21769164720 is a wasteful number, since it uses less digits than its factorization.

21769164720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12103 (or 12082 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 45.

The spelling of 21769164720 in words is "twenty-one billion, seven hundred sixty-nine million, one hundred sixty-four thousand, seven hundred twenty".