21965428747 has 2 divisors, whose sum is σ = 21965428748. Its totient is φ = 21965428746.

The previous prime is 21965428739. The next prime is 21965428753. The reversal of 21965428747 is 74782456912.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21965428747 - 2³ = 21965428739 is a prime.

It is not a weakly prime, because it can be changed into another prime (21965423747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10982714373 + 10982714374.

It is an arithmetic number, because the mean of its divisors is an integer number (10982714374).

Almost surely, 2^21965428747 is an apocalyptic number.

21965428747 is a deficient number, since it is larger than the sum of its proper divisors (1).

21965428747 is an equidigital number, since it uses as much as digits as its factorization.

21965428747 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6773760, while the sum is 55.

The spelling of 21965428747 in words is "twenty-one billion, nine hundred sixty-five million, four hundred twenty-eight thousand, seven hundred forty-seven".