21260333647 has 16 divisors (see below), whose sum is σ = 24500980800. Its totient is φ = 18070956288.

The previous prime is 21260333623. The next prime is 21260333657. The reversal of 21260333647 is 74633306212.

It is not a de Polignac number, because 21260333647 - 2⁷ = 21260333519 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21260333657) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 627013 + ... + 660049.

It is an arithmetic number, because the mean of its divisors is an integer number (1531311300).

Almost surely, 2^21260333647 is an apocalyptic number.

21260333647 is a deficient number, since it is larger than the sum of its proper divisors (3240647153).

21260333647 is a wasteful number, since it uses less digits than its factorization.

21260333647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33810.

The product of its (nonzero) digits is 108864, while the sum is 37.

Adding to 21260333647 its reverse (74633306212), we get a palindrome (95893639859).

The spelling of 21260333647 in words is "twenty-one billion, two hundred sixty million, three hundred thirty-three thousand, six hundred forty-seven".