21109746 has 16 divisors (see below), whose sum is σ = 48250944. Its totient is φ = 6031344.

The previous prime is 21109727. The next prime is 21109763. The reversal of 21109746 is 64790112.

It is a happy number.

It is a Curzon number.

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, 251265 + ... + 251348.

It is an arithmetic number, because the mean of its divisors is an integer number (3015684).

Almost surely, 2^21109746 is an apocalyptic number.

21109746 is an abundant number, since it is smaller than the sum of its proper divisors (27141198).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21109746 is a wasteful number, since it uses less digits than its factorization.

21109746 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502625.

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 21109746 is about 4594.5343616084. The cubic root of 21109746 is about 276.3721874387.

Adding to 21109746 its reverse (64790112), we get a palindrome (85899858).

The spelling of 21109746 in words is "twenty-one million, one hundred nine thousand, seven hundred forty-six".