21609046 has 12 divisors (see below), whose sum is σ = 33495876. Its totient is φ = 10455060.

The previous prime is 21609037. The next prime is 21609053. The reversal of 21609046 is 64090612.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3700 + ... + 7543.

It is an arithmetic number, because the mean of its divisors is an integer number (2791323).

Almost surely, 2^21609046 is an apocalyptic number.

21609046 is a deficient number, since it is larger than the sum of its proper divisors (11886830).

21609046 is a wasteful number, since it uses less digits than its factorization.

21609046 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11307 (or 11276 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 21609046 is about 4648.5531082263. The cubic root of 21609046 is about 278.5342021950.

Adding to 21609046 its reverse (64090612), we get a palindrome (85699658).

The spelling of 21609046 in words is "twenty-one million, six hundred nine thousand, forty-six".