21610906 has 8 divisors (see below), whose sum is σ = 33462144. Its totient is φ = 10456860.

The previous prime is 21610889. The next prime is 21610907. The reversal of 21610906 is 60901612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21610907) 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 3 ways as a sum of consecutive naturals, for example, 174220 + ... + 174343.

It is an arithmetic number, because the mean of its divisors is an integer number (4182768).

Almost surely, 2^21610906 is an apocalyptic number.

21610906 is a deficient number, since it is larger than the sum of its proper divisors (11851238).

21610906 is a wasteful number, since it uses less digits than its factorization.

21610906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 348596.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 21610906 is about 4648.7531661726. The cubic root of 21610906 is about 278.5421935821.

The spelling of 21610906 in words is "twenty-one million, six hundred ten thousand, nine hundred six".