21105634 has 16 divisors (see below), whose sum is σ = 35104896. Its totient is φ = 9435600.

The previous prime is 21105587. The next prime is 21105641. The reversal of 21105634 is 43650112.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6522 + ... + 9205.

It is an arithmetic number, because the mean of its divisors is an integer number (2194056).

Almost surely, 2^21105634 is an apocalyptic number.

21105634 is a deficient number, since it is larger than the sum of its proper divisors (13999262).

21105634 is a wasteful number, since it uses less digits than its factorization.

21105634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15801.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 21105634 is about 4594.0868515952. The cubic root of 21105634 is about 276.3542412851.

Adding to 21105634 its reverse (43650112), we get a palindrome (64755746).

It can be divided in two parts, 2110 and 5634, that added together give a square (7744 = 88²).

The spelling of 21105634 in words is "twenty-one million, one hundred five thousand, six hundred thirty-four".