21264644511 has 24 divisors (see below), whose sum is σ = 33517201536. Its totient is φ = 12884095440.

The previous prime is 21264644491. The next prime is 21264644521. The reversal of 21264644511 is 11544646212.

21264644511 is a `hidden beast` number, since 2 + 1 + 2 + 6 + 4 + 644 + 5 + 1 + 1 = 666.

It is not a de Polignac number, because 21264644511 - 2¹⁰ = 21264643487 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21264644521) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 354636 + ... + 410238.

It is an arithmetic number, because the mean of its divisors is an integer number (1396550064).

Almost surely, 2^21264644511 is an apocalyptic number.

21264644511 is a deficient number, since it is larger than the sum of its proper divisors (12252557025).

21264644511 is a wasteful number, since it uses less digits than its factorization.

21264644511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59483 (or 59480 counting only the distinct ones).

The product of its digits is 46080, while the sum is 36.

The spelling of 21264644511 in words is "twenty-one billion, two hundred sixty-four million, six hundred forty-four thousand, five hundred eleven".