21635804 has 6 divisors (see below), whose sum is σ = 37862664. Its totient is φ = 10817900.

The previous prime is 21635749. The next prime is 21635807. The reversal of 21635804 is 40853612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21635807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2704472 + ... + 2704479.

It is an arithmetic number, because the mean of its divisors is an integer number (6310444).

Almost surely, 2^21635804 is an apocalyptic number.

It is an amenable number.

21635804 is a deficient number, since it is larger than the sum of its proper divisors (16226860).

21635804 is a wasteful number, since it uses less digits than its factorization.

21635804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5408955 (or 5408953 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 21635804 is about 4651.4303176550. The cubic root of 21635804 is about 278.6491223384.

The spelling of 21635804 in words is "twenty-one million, six hundred thirty-five thousand, eight hundred four".