21065770 has 16 divisors (see below), whose sum is σ = 41365728. Its totient is φ = 7660240.

The previous prime is 21065767. The next prime is 21065777. The reversal of 21065770 is 7756012.

It is not an unprimeable number, because it can be changed into a prime (21065777) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95644 + ... + 95863.

It is an arithmetic number, because the mean of its divisors is an integer number (2585358).

Almost surely, 2^21065770 is an apocalyptic number.

21065770 is a deficient number, since it is larger than the sum of its proper divisors (20299958).

21065770 is a wasteful number, since it uses less digits than its factorization.

21065770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191525.

The product of its (nonzero) digits is 2940, while the sum is 28.

The square root of 21065770 is about 4589.7461803459. The cubic root of 21065770 is about 276.1801403989.

The spelling of 21065770 in words is "twenty-one million, sixty-five thousand, seven hundred seventy".