21947899932 has 288 divisors, whose sum is σ = 69955092480. Its totient is φ = 5660772480.

The previous prime is 21947899931. The next prime is 21947899943. The reversal of 21947899932 is 23999874912.

It is a super-2 number, since 2×21947899932² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a self number, because there is not a number n which added to its sum of digits gives 21947899932.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21947899931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9943573 + ... + 9945779.

Almost surely, 2^21947899932 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 21947899932, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34977546240).

21947899932 is an abundant number, since it is smaller than the sum of its proper divisors (48007192548).

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

21947899932 is a wasteful number, since it uses less digits than its factorization.

21947899932 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2341 (or 2336 counting only the distinct ones).

The product of its digits is 17635968, while the sum is 63.

The spelling of 21947899932 in words is "twenty-one billion, nine hundred forty-seven million, eight hundred ninety-nine thousand, nine hundred thirty-two".