21213374 has 24 divisors (see below), whose sum is σ = 39864888. Its totient is φ = 8391600.

The previous prime is 21213373. The next prime is 21213407. The reversal of 21213374 is 47331212.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213373) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 7052 + ... + 9599.

It is an arithmetic number, because the mean of its divisors is an integer number (1661037).

Almost surely, 2^21213374 is an apocalyptic number.

21213374 is a deficient number, since it is larger than the sum of its proper divisors (18651514).

21213374 is a wasteful number, since it uses less digits than its factorization.

21213374 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16680 (or 16673 counting only the distinct ones).

The product of its digits is 1008, while the sum is 23.

The square root of 21213374 is about 4605.7978679052. The cubic root of 21213374 is about 276.8236875799.

Adding to 21213374 its reverse (47331212), we get a palindrome (68544586).

The spelling of 21213374 in words is "twenty-one million, two hundred thirteen thousand, three hundred seventy-four".