21331774751 has 4 divisors (see below), whose sum is σ = 24379171152. Its totient is φ = 18284378352.

The previous prime is 21331774747. The next prime is 21331774757. The reversal of 21331774751 is 15747713312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21331774751 - 2² = 21331774747 is a prime.

It is a super-2 number, since 2×21331774751² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21331774699 and 21331774708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331774757) 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, 1523698190 + ... + 1523698203.

It is an arithmetic number, because the mean of its divisors is an integer number (6094792788).

Almost surely, 2^21331774751 is an apocalyptic number.

21331774751 is a deficient number, since it is larger than the sum of its proper divisors (3047396401).

21331774751 is an equidigital number, since it uses as much as digits as its factorization.

21331774751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3047396400.

The product of its digits is 123480, while the sum is 41.

The spelling of 21331774751 in words is "twenty-one billion, three hundred thirty-one million, seven hundred seventy-four thousand, seven hundred fifty-one".