21020270 has 32 divisors (see below), whose sum is σ = 40068000. Its totient is φ = 7917696.

The previous prime is 21020269. The next prime is 21020281. The reversal of 21020270 is 7202012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60056 + ... + 60404.

It is an arithmetic number, because the mean of its divisors is an integer number (1252125).

Almost surely, 2^21020270 is an apocalyptic number.

21020270 is a deficient number, since it is larger than the sum of its proper divisors (19047730).

21020270 is a wasteful number, since it uses less digits than its factorization.

21020270 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 692.

The product of its (nonzero) digits is 56, while the sum is 14.

The square root of 21020270 is about 4584.7867998414. The cubic root of 21020270 is about 275.9811563835.

Adding to 21020270 its reverse (7202012), we get a palindrome (28222282).

The spelling of 21020270 in words is "twenty-one million, twenty thousand, two hundred seventy".