21989699424 has 576 divisors, whose sum is σ = 84970529280. Its totient is φ = 5460618240.

The previous prime is 21989699357. The next prime is 21989699443. The reversal of 21989699424 is 42499698912.

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

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 10709982 + ... + 10712034.

It is an arithmetic number, because the mean of its divisors is an integer number (147518280).

Almost surely, 2^21989699424 is an apocalyptic number.

21989699424 is a gapful number since it is divisible by the number (24) 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 21989699424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42485264640).

21989699424 is an abundant number, since it is smaller than the sum of its proper divisors (62980829856).

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

21989699424 is a wasteful number, since it uses less digits than its factorization.

21989699424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2120 (or 2099 counting only the distinct ones).

The product of its digits is 20155392, while the sum is 63.

The spelling of 21989699424 in words is "twenty-one billion, nine hundred eighty-nine million, six hundred ninety-nine thousand, four hundred twenty-four".