21145792820 has 48 divisors (see below), whose sum is σ = 44545892160. Its totient is φ = 8431755264.

The previous prime is 21145792799. The next prime is 21145792823. The reversal of 21145792820 is 2829754112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21145792823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12103187 + ... + 12104933.

It is an arithmetic number, because the mean of its divisors is an integer number (928039420).

Almost surely, 2^21145792820 is an apocalyptic number.

21145792820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21145792820 is an abundant number, since it is smaller than the sum of its proper divisors (23400099340).

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

21145792820 is a wasteful number, since it uses less digits than its factorization.

21145792820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3312 (or 3310 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 41.

The spelling of 21145792820 in words is "twenty-one billion, one hundred forty-five million, seven hundred ninety-two thousand, eight hundred twenty".