21026364 has 12 divisors (see below), whose sum is σ = 49061544. Its totient is φ = 7008784.

The previous prime is 21026359. The next prime is 21026371. The reversal of 21026364 is 46362012.

It is a tau number, because it is divible by the number of its divisors (12).

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 3 ways as a sum of consecutive naturals, for example, 876087 + ... + 876110.

It is an arithmetic number, because the mean of its divisors is an integer number (4088462).

Almost surely, 2^21026364 is an apocalyptic number.

It is an amenable number.

21026364 is an abundant number, since it is smaller than the sum of its proper divisors (28035180).

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

21026364 is a wasteful number, since it uses less digits than its factorization.

21026364 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1752204 (or 1752202 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 21026364 is about 4585.4513409260. The cubic root of 21026364 is about 276.0078237648.

Adding to 21026364 its reverse (46362012), we get a palindrome (67388376).

The spelling of 21026364 in words is "twenty-one million, twenty-six thousand, three hundred sixty-four".