21764535 has 32 divisors (see below), whose sum is σ = 37739520. Its totient is φ = 10647168.

The previous prime is 21764513. The next prime is 21764537. The reversal of 21764535 is 53546712.

It is not a de Polignac number, because 21764535 - 2¹⁵ = 21731767 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21764496 and 21764505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21764537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 46372 + ... + 46838.

It is an arithmetic number, because the mean of its divisors is an integer number (1179360).

Almost surely, 2^21764535 is an apocalyptic number.

21764535 is a deficient number, since it is larger than the sum of its proper divisors (15974985).

21764535 is a wasteful number, since it uses less digits than its factorization.

21764535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 727.

The product of its digits is 25200, while the sum is 33.

The square root of 21764535 is about 4665.2475818546. The cubic root of 21764535 is about 279.2006752460.

The spelling of 21764535 in words is "twenty-one million, seven hundred sixty-four thousand, five hundred thirty-five".