21033670 has 16 divisors (see below), whose sum is σ = 43269408. Its totient is φ = 7211520.

The previous prime is 21033667. The next prime is 21033721. The reversal of 21033670 is 7633012.

21033670 = 1016² + 1017² + ... + 1035².

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 150171 + ... + 150310.

It is an arithmetic number, because the mean of its divisors is an integer number (2704338).

Almost surely, 2^21033670 is an apocalyptic number.

21033670 is an abundant number, since it is smaller than the sum of its proper divisors (22235738).

21033670 is a wasteful number, since it uses less digits than its factorization.

21033670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300495.

The product of its (nonzero) digits is 756, while the sum is 22.

The square root of 21033670 is about 4586.2479217766. The cubic root of 21033670 is about 276.0397880747.

Adding to 21033670 its reverse (7633012), we get a palindrome (28666682).

The spelling of 21033670 in words is "twenty-one million, thirty-three thousand, six hundred seventy".