21210994 has 16 divisors (see below), whose sum is σ = 36906048. Its totient is φ = 8954352.

The previous prime is 21210989. The next prime is 21211009. The reversal of 21210994 is 49901212.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10369 + ... + 12244.

It is an arithmetic number, because the mean of its divisors is an integer number (2306628).

Almost surely, 2^21210994 is an apocalyptic number.

21210994 is a deficient number, since it is larger than the sum of its proper divisors (15695054).

21210994 is a wasteful number, since it uses less digits than its factorization.

21210994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22689.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 21210994 is about 4605.5394906569. The cubic root of 21210994 is about 276.8133345982.

The spelling of 21210994 in words is "twenty-one million, two hundred ten thousand, nine hundred ninety-four".