21606770 has 8 divisors (see below), whose sum is σ = 38892204. Its totient is φ = 8642704.

The previous prime is 21606757. The next prime is 21606787. The reversal of 21606770 is 7760612.

It can be written as a sum of positive squares in 2 ways, for example, as 18498601 + 3108169 = 4301^2 + 1763^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1080329 + ... + 1080348.

Almost surely, 2^21606770 is an apocalyptic number.

21606770 is a deficient number, since it is larger than the sum of its proper divisors (17285434).

21606770 is a wasteful number, since it uses less digits than its factorization.

21606770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2160684.

The product of its (nonzero) digits is 3528, while the sum is 29.

The square root of 21606770 is about 4648.3082944228. The cubic root of 21606770 is about 278.5244228631.

The spelling of 21606770 in words is "twenty-one million, six hundred six thousand, seven hundred seventy".