21764747635 has 4 divisors (see below), whose sum is σ = 26117697168. Its totient is φ = 17411798104.

The previous prime is 21764747633. The next prime is 21764747657. The reversal of 21764747635 is 53674746712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21764747635 - 2¹ = 21764747633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21764747633) 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 3 ways as a sum of consecutive naturals, for example, 2176474759 + ... + 2176474768.

It is an arithmetic number, because the mean of its divisors is an integer number (6529424292).

Almost surely, 2^21764747635 is an apocalyptic number.

21764747635 is a deficient number, since it is larger than the sum of its proper divisors (4352949533).

21764747635 is an equidigital number, since it uses as much as digits as its factorization.

21764747635 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4352949532.

The product of its digits is 5927040, while the sum is 52.

The spelling of 21764747635 in words is "twenty-one billion, seven hundred sixty-four million, seven hundred forty-seven thousand, six hundred thirty-five".