21997968113 has 4 divisors (see below), whose sum is σ = 23997783408. Its totient is φ = 19998152820.

The previous prime is 21997968073. The next prime is 21997968119. The reversal of 21997968113 is 31186979912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21997968113 - 2⁸ = 21997967857 is a prime.

It is a super-2 number, since 2×21997968113² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21997968119) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 999907631 + ... + 999907652.

It is an arithmetic number, because the mean of its divisors is an integer number (5999445852).

Almost surely, 2^21997968113 is an apocalyptic number.

It is an amenable number.

21997968113 is a deficient number, since it is larger than the sum of its proper divisors (1999815295).

21997968113 is a wasteful number, since it uses less digits than its factorization.

21997968113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1999815294.

The product of its digits is 1469664, while the sum is 56.

The spelling of 21997968113 in words is "twenty-one billion, nine hundred ninety-seven million, nine hundred sixty-eight thousand, one hundred thirteen".