21998711712 has 192 divisors, whose sum is σ = 60907037184. Its totient is φ = 6944071680.

The previous prime is 21998711711. The next prime is 21998711737. The reversal of 21998711712 is 21711789912.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (21998711711) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 52253262 + ... + 52253682.

It is an arithmetic number, because the mean of its divisors is an integer number (317224152).

Almost surely, 2^21998711712 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 21998711712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30453518592).

21998711712 is an abundant number, since it is smaller than the sum of its proper divisors (38908325472).

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

21998711712 is a wasteful number, since it uses less digits than its factorization.

21998711712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 831 (or 823 counting only the distinct ones).

The product of its digits is 127008, while the sum is 48.

The spelling of 21998711712 in words is "twenty-one billion, nine hundred ninety-eight million, seven hundred eleven thousand, seven hundred twelve".