21943528380 has 288 divisors, whose sum is σ = 69267115008. Its totient is φ = 5620608000.

The previous prime is 21943528363. The next prime is 21943528391. The reversal of 21943528380 is 8382534912.

21943528380 is a `hidden beast` number, since 2 + 1 + 9 + 43 + 528 + 3 + 80 = 666.

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 pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 145321305 + ... + 145321455.

It is an arithmetic number, because the mean of its divisors is an integer number (240510816).

Almost surely, 2^21943528380 is an apocalyptic number.

21943528380 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 21943528380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34633557504).

21943528380 is an abundant number, since it is smaller than the sum of its proper divisors (47323586628).

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

21943528380 is a wasteful number, since it uses less digits than its factorization.

21943528380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 457 (or 452 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The spelling of 21943528380 in words is "twenty-one billion, nine hundred forty-three million, five hundred twenty-eight thousand, three hundred eighty".