21230276665 has 8 divisors (see below), whose sum is σ = 27436049928. Its totient is φ = 15677742720.

The previous prime is 21230276663. The next prime is 21230276687. The reversal of 21230276665 is 56667203212.

It can be written as a sum of positive squares in 4 ways, for example, as 53042089 + 21177234576 = 7283^2 + 145524^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21230276665 - 2¹ = 21230276663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21230276663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 163309756 + ... + 163309885.

It is an arithmetic number, because the mean of its divisors is an integer number (3429506241).

Almost surely, 2^21230276665 is an apocalyptic number.

It is an amenable number.

21230276665 is a deficient number, since it is larger than the sum of its proper divisors (6205773263).

21230276665 is a wasteful number, since it uses less digits than its factorization.

21230276665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 326619659.

The product of its (nonzero) digits is 181440, while the sum is 40.

Adding to 21230276665 its reverse (56667203212), we get a palindrome (77897479877).

The spelling of 21230276665 in words is "twenty-one billion, two hundred thirty million, two hundred seventy-six thousand, six hundred sixty-five".