21547634 has 16 divisors (see below), whose sum is σ = 34279200. Its totient is φ = 10129824.

The previous prime is 21547621. The next prime is 21547637. The reversal of 21547634 is 43674512.

It is a self number, because there is not a number n which added to its sum of digits gives 21547634.

It is not an unprimeable number, because it can be changed into a prime (21547637) 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 in 7 ways as a sum of consecutive naturals, for example, 3137 + ... + 7275.

It is an arithmetic number, because the mean of its divisors is an integer number (2142450).

Almost surely, 2^21547634 is an apocalyptic number.

21547634 is a deficient number, since it is larger than the sum of its proper divisors (12731566).

21547634 is a wasteful number, since it uses less digits than its factorization.

21547634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4297.

The product of its digits is 20160, while the sum is 32.

The square root of 21547634 is about 4641.9429121867. The cubic root of 21547634 is about 278.2700910094.

The spelling of 21547634 in words is "twenty-one million, five hundred forty-seven thousand, six hundred thirty-four".