21430443277 has 2 divisors, whose sum is σ = 21430443278. Its totient is φ = 21430443276.

The previous prime is 21430443247. The next prime is 21430443317. The reversal of 21430443277 is 77234403412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17500908681 + 3929534596 = 132291^2 + 62686^2 .

It is a cyclic number.

It is not a de Polignac number, because 21430443277 - 2⁷ = 21430443149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21430443227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10715221638 + 10715221639.

It is an arithmetic number, because the mean of its divisors is an integer number (10715221639).

Almost surely, 2^21430443277 is an apocalyptic number.

It is an amenable number.

21430443277 is a deficient number, since it is larger than the sum of its proper divisors (1).

21430443277 is an equidigital number, since it uses as much as digits as its factorization.

21430443277 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112896, while the sum is 37.

Adding to 21430443277 its reverse (77234403412), we get a palindrome (98664846689).

The spelling of 21430443277 in words is "twenty-one billion, four hundred thirty million, four hundred forty-three thousand, two hundred seventy-seven".