21820199472 has 80 divisors (see below), whose sum is σ = 62694082560. Its totient is φ = 7266196800.

The previous prime is 21820199441. The next prime is 21820199519. The reversal of 21820199472 is 27499102812.

It is a super-2 number, since 2×21820199472² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 420897 + ... + 469887.

It is an arithmetic number, because the mean of its divisors is an integer number (783676032).

Almost surely, 2^21820199472 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 21820199472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31347041280).

21820199472 is an abundant number, since it is smaller than the sum of its proper divisors (40873883088).

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

21820199472 is a wasteful number, since it uses less digits than its factorization.

21820199472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50039 (or 50027 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The spelling of 21820199472 in words is "twenty-one billion, eight hundred twenty million, one hundred ninety-nine thousand, four hundred seventy-two".