21146323968 has 990 divisors, whose sum is σ = 82619466468. Its totient is φ = 5364817920.

The previous prime is 21146323967. The next prime is 21146324009. The reversal of 21146323968 is 86932364112.

21146323968 is a `hidden beast` number, since 2 + 1 + 1 + 4 + 632 + 3 + 9 + 6 + 8 = 666.

It is a super-2 number, since 2×21146323968² (a number of 21 digits) contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (21146323963) by changing a digit.

It is a polite number, since it can be written in 89 ways as a sum of consecutive naturals, for example, 491774955 + ... + 491774997.

Almost surely, 2^21146323968 is an apocalyptic number.

21146323968 is a gapful number since it is divisible by the number (28) 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 21146323968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41309733234).

21146323968 is an abundant number, since it is smaller than the sum of its proper divisors (61473142500).

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

21146323968 is a wasteful number, since it uses less digits than its factorization.

21146323968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111 (or 66 counting only the distinct ones).

The product of its digits is 373248, while the sum is 45.

The spelling of 21146323968 in words is "twenty-one billion, one hundred forty-six million, three hundred twenty-three thousand, nine hundred sixty-eight".