21000034 has 24 divisors (see below), whose sum is σ = 34990704. Its totient is φ = 9444600.

The previous prime is 20999999. The next prime is 21000037. The reversal of 21000034 is 43000012.

It is not an unprimeable number, because it can be changed into a prime (21000037) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 25489 + ... + 26299.

It is an arithmetic number, because the mean of its divisors is an integer number (1457946).

Almost surely, 2^21000034 is an apocalyptic number.

21000034 is a deficient number, since it is larger than the sum of its proper divisors (13990670).

21000034 is a wasteful number, since it uses less digits than its factorization.

21000034 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 942 (or 931 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 10.

The square root of 21000034 is about 4582.5794046585. The cubic root of 21000034 is about 275.8925665324.

Adding to 21000034 its reverse (43000012), we get a palindrome (64000046).

The spelling of 21000034 in words is "twenty-one million, thirty-four", and thus it is an aban number.