21106634 has 4 divisors (see below), whose sum is σ = 31659954. Its totient is φ = 10553316.

The previous prime is 21106607. The next prime is 21106643. The reversal of 21106634 is 43660112.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 14100025 + 7006609 = 3755^2 + 2647^2 .

It is an unprimeable number.

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, 5276657 + ... + 5276660.

Almost surely, 2^21106634 is an apocalyptic number.

21106634 is a deficient number, since it is larger than the sum of its proper divisors (10553320).

21106634 is a wasteful number, since it uses less digits than its factorization.

21106634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10553319.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 21106634 is about 4594.1956858628. The cubic root of 21106634 is about 276.3586058366.

Adding to 21106634 its reverse (43660112), we get a palindrome (64766746).

The spelling of 21106634 in words is "twenty-one million, one hundred six thousand, six hundred thirty-four".