21123196 has 6 divisors (see below), whose sum is σ = 36965600. Its totient is φ = 10561596.

The previous prime is 21123187. The next prime is 21123211. The reversal of 21123196 is 69132112.

It is a self number, because there is not a number n which added to its sum of digits gives 21123196.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2640396 + ... + 2640403.

Almost surely, 2^21123196 is an apocalyptic number.

It is an amenable number.

21123196 is a deficient number, since it is larger than the sum of its proper divisors (15842404).

21123196 is a wasteful number, since it uses less digits than its factorization.

21123196 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5280803 (or 5280801 counting only the distinct ones).

The product of its digits is 648, while the sum is 25.

The square root of 21123196 is about 4595.9978241944. The cubic root of 21123196 is about 276.4308714976.

The spelling of 21123196 in words is "twenty-one million, one hundred twenty-three thousand, one hundred ninety-six".