21973688100 has 864 divisors, whose sum is σ = 92712954880. Its totient is φ = 4383797760.

The previous prime is 21973688071. The next prime is 21973688101. The reversal of 21973688100 is 188637912.

It is a super-2 number, since 2×21973688100² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (21973688101) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 42014439 + ... + 42014961.

Almost surely, 2^21973688100 is an apocalyptic number.

21973688100 is a gapful number since it is divisible by the number (20) 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 21973688100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46356477440).

21973688100 is an abundant number, since it is smaller than the sum of its proper divisors (70739266780).

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

21973688100 is a wasteful number, since it uses less digits than its factorization.

21973688100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 591 (or 572 counting only the distinct ones).

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

The spelling of 21973688100 in words is "twenty-one billion, nine hundred seventy-three million, six hundred eighty-eight thousand, one hundred".