21545937792 has 160 divisors (see below), whose sum is σ = 66908944080. Its totient is φ = 6869643264.

The previous prime is 21545937779. The next prime is 21545937797. The reversal of 21545937792 is 29773954512.

21545937792 is a `hidden beast` number, since 2 + 1 + 545 + 9 + 3 + 7 + 7 + 92 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21545937797) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 193288 + ... + 283640.

Almost surely, 2^21545937792 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21545937792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33454472040).

21545937792 is an abundant number, since it is smaller than the sum of its proper divisors (45363006288).

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

21545937792 is an equidigital number, since it uses as much as digits as its factorization.

21545937792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90402 (or 90381 counting only the distinct ones).

The product of its digits is 4762800, while the sum is 54.

The spelling of 21545937792 in words is "twenty-one billion, five hundred forty-five million, nine hundred thirty-seven thousand, seven hundred ninety-two".