21264847791 has 32 divisors (see below), whose sum is σ = 31502960640. Its totient is φ = 12650008800.

The previous prime is 21264847787. The next prime is 21264847801. The reversal of 21264847791 is 19774846212.

It is not a de Polignac number, because 21264847791 - 2² = 21264847787 is a prime.

It is a super-3 number, since 3×21264847791³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21264847391) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1321806 + ... + 1337796.

It is an arithmetic number, because the mean of its divisors is an integer number (984467520).

Almost surely, 2^21264847791 is an apocalyptic number.

21264847791 is a deficient number, since it is larger than the sum of its proper divisors (10238112849).

21264847791 is a wasteful number, since it uses less digits than its factorization.

21264847791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16747.

The product of its digits is 1354752, while the sum is 51.

The spelling of 21264847791 in words is "twenty-one billion, two hundred sixty-four million, eight hundred forty-seven thousand, seven hundred ninety-one".