21020675 has 12 divisors (see below), whose sum is σ = 28071120. Its totient is φ = 15522720.

The previous prime is 21020651. The next prime is 21020683. The reversal of 21020675 is 57602012.

It is not a de Polignac number, because 21020675 - 2⁶ = 21020611 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21020675.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32015 + ... + 32664.

It is an arithmetic number, because the mean of its divisors is an integer number (2339260).

Almost surely, 2^21020675 is an apocalyptic number.

21020675 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21020675 is a deficient number, since it is larger than the sum of its proper divisors (7050445).

21020675 is a wasteful number, since it uses less digits than its factorization.

21020675 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64702 (or 64697 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 21020675 is about 4584.8309674403. The cubic root of 21020675 is about 275.9829288258.

Adding to 21020675 its reverse (57602012), we get a palindrome (78622687).

The spelling of 21020675 in words is "twenty-one million, twenty thousand, six hundred seventy-five".