21697898976 has 240 divisors, whose sum is σ = 71712061344. Its totient is φ = 6385775616.

The previous prime is 21697898969. The next prime is 21697899007. The reversal of 21697898976 is 67989879612.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 761010 + ... + 789006.

Almost surely, 2^21697898976 is an apocalyptic number.

21697898976 is a gapful number since it is divisible by the number (26) 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 21697898976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35856030672).

21697898976 is an abundant number, since it is smaller than the sum of its proper divisors (50014162368).

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

21697898976 is a wasteful number, since it uses less digits than its factorization.

21697898976 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28055 (or 28038 counting only the distinct ones).

The product of its digits is 164602368, while the sum is 72.

The spelling of 21697898976 in words is "twenty-one billion, six hundred ninety-seven million, eight hundred ninety-eight thousand, nine hundred seventy-six".