21919234 has 4 divisors (see below), whose sum is σ = 32878854. Its totient is φ = 10959616.

The previous prime is 21919223. The next prime is 21919237. The reversal of 21919234 is 43291912.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 18105025 + 3814209 = 4255^2 + 1953^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21919196 and 21919205.

It is not an unprimeable number, because it can be changed into a prime (21919237) 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 as a sum of consecutive naturals, namely, 5479807 + ... + 5479810.

Almost surely, 2^21919234 is an apocalyptic number.

21919234 is a deficient number, since it is larger than the sum of its proper divisors (10959620).

21919234 is a wasteful number, since it uses less digits than its factorization.

21919234 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10959619.

The product of its digits is 3888, while the sum is 31.

The square root of 21919234 is about 4681.7981588274. The cubic root of 21919234 is about 279.8606194051.

The spelling of 21919234 in words is "twenty-one million, nine hundred nineteen thousand, two hundred thirty-four".