21921269760 has 960 divisors, whose sum is σ = 89902612800. Its totient is φ = 5064228864.

The previous prime is 21921269729. The next prime is 21921269761. The reversal of 21921269760 is 6796212912.

It is a tau number, because it is divible by the number of its divisors (960).

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

It is not an unprimeable number, because it can be changed into a prime (21921269761) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 204871627 + ... + 204871733.

It is an arithmetic number, because the mean of its divisors is an integer number (93648555).

Almost surely, 2^21921269760 is an apocalyptic number.

21921269760 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 21921269760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44951306400).

21921269760 is an abundant number, since it is smaller than the sum of its proper divisors (67981343040).

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

21921269760 is a wasteful number, since it uses less digits than its factorization.

21921269760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178 (or 149 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The spelling of 21921269760 in words is "twenty-one billion, nine hundred twenty-one million, two hundred sixty-nine thousand, seven hundred sixty".