21264212761 has 8 divisors (see below), whose sum is σ = 23824278144. Its totient is φ = 18808639920.

The previous prime is 21264212743. The next prime is 21264212777. The reversal of 21264212761 is 16721246212.

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

It is a cyclic number.

It is not a de Polignac number, because 21264212761 - 2¹¹ = 21264210713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21264210761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26122705 + ... + 26123518.

It is an arithmetic number, because the mean of its divisors is an integer number (2978034768).

Almost surely, 2^21264212761 is an apocalyptic number.

It is an amenable number.

21264212761 is a deficient number, since it is larger than the sum of its proper divisors (2560065383).

21264212761 is a wasteful number, since it uses less digits than its factorization.

21264212761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52246271.

The product of its digits is 16128, while the sum is 34.

Adding to 21264212761 its reverse (16721246212), we get a palindrome (37985458973).

The spelling of 21264212761 in words is "twenty-one billion, two hundred sixty-four million, two hundred twelve thousand, seven hundred sixty-one".