21020946 has 16 divisors (see below), whose sum is σ = 43067808. Its totient is φ = 6836000.

The previous prime is 21020941. The next prime is 21020947. The reversal of 21020946 is 64902012.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21020941) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 42480 + ... + 42971.

It is an arithmetic number, because the mean of its divisors is an integer number (2691738).

Almost surely, 2^21020946 is an apocalyptic number.

21020946 is an abundant number, since it is smaller than the sum of its proper divisors (22046862).

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

21020946 is a wasteful number, since it uses less digits than its factorization.

21020946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85497.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 21020946 is about 4584.8605213245. The cubic root of 21020946 is about 275.9841148177.

Adding to 21020946 its reverse (64902012), we get a palindrome (85922958).

The spelling of 21020946 in words is "twenty-one million, twenty thousand, nine hundred forty-six".