21276859969 has 4 divisors (see below), whose sum is σ = 21278760660. Its totient is φ = 21274959280.

The previous prime is 21276859943. The next prime is 21276859973. The reversal of 21276859969 is 96995867212.

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

It can be written as a sum of positive squares in 2 ways, for example, as 14692348944 + 6584511025 = 121212^2 + 81145^2 .

It is a cyclic number.

It is not a de Polignac number, because 21276859969 - 2¹⁷ = 21276728897 is a prime.

It is a super-2 number, since 2×21276859969² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21276859969.

It is not an unprimeable number, because it can be changed into a prime (21276859979) 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, 933454 + ... + 955975.

It is an arithmetic number, because the mean of its divisors is an integer number (5319690165).

Almost surely, 2^21276859969 is an apocalyptic number.

It is an amenable number.

21276859969 is a deficient number, since it is larger than the sum of its proper divisors (1900691).

21276859969 is a wasteful number, since it uses less digits than its factorization.

21276859969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1900690.

The product of its digits is 29393280, while the sum is 64.

The spelling of 21276859969 in words is "twenty-one billion, two hundred seventy-six million, eight hundred fifty-nine thousand, nine hundred sixty-nine".