21279422737 has 2 divisors, whose sum is σ = 21279422738. Its totient is φ = 21279422736.

The previous prime is 21279422677. The next prime is 21279422741. The reversal of 21279422737 is 73722497212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19732101841 + 1547320896 = 140471^2 + 39336^2 .

It is a cyclic number.

It is not a de Polignac number, because 21279422737 - 2¹⁵ = 21279389969 is a prime.

It is not a weakly prime, because it can be changed into another prime (21279422237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10639711368 + 10639711369.

It is an arithmetic number, because the mean of its divisors is an integer number (10639711369).

Almost surely, 2^21279422737 is an apocalyptic number.

It is an amenable number.

21279422737 is a deficient number, since it is larger than the sum of its proper divisors (1).

21279422737 is an equidigital number, since it uses as much as digits as its factorization.

21279422737 is an evil number, because the sum of its binary digits is even.

The product of its digits is 592704, while the sum is 46.

The spelling of 21279422737 in words is "twenty-one billion, two hundred seventy-nine million, four hundred twenty-two thousand, seven hundred thirty-seven".