21266570 has 32 divisors (see below), whose sum is σ = 42653520. Its totient is φ = 7580160.

The previous prime is 21266561. The next prime is 21266603. The reversal of 21266570 is 7566212.

It can be written as a sum of positive squares in 8 ways, for example, as 12439729 + 8826841 = 3527^2 + 2971^2 .

It is a Harshad number since it is a multiple of its sum of digits (29).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 950 + ... + 6590.

Almost surely, 2^21266570 is an apocalyptic number.

21266570 is an abundant number, since it is smaller than the sum of its proper divisors (21386950).

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

21266570 is a wasteful number, since it uses less digits than its factorization.

21266570 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5690.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 21266570 is about 4611.5691472643. The cubic root of 21266570 is about 277.0548879663.

The spelling of 21266570 in words is "twenty-one million, two hundred sixty-six thousand, five hundred seventy".