21321004 has 6 divisors (see below), whose sum is σ = 37311764. Its totient is φ = 10660500.

The previous prime is 21320987. The next prime is 21321019. The reversal of 21321004 is 40012312.

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 as a sum of consecutive naturals, namely, 2665122 + ... + 2665129.

Almost surely, 2^21321004 is an apocalyptic number.

It is an amenable number.

21321004 is a deficient number, since it is larger than the sum of its proper divisors (15990760).

21321004 is a wasteful number, since it uses less digits than its factorization.

21321004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5330255 (or 5330253 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21321004 is about 4617.4672711347. The cubic root of 21321004 is about 277.2910701798.

Adding to 21321004 its reverse (40012312), we get a palindrome (61333316).

It can be divided in two parts, 2132 and 1004, that added together give a square (3136 = 56²).

The spelling of 21321004 in words is "twenty-one million, three hundred twenty-one thousand, four".