21193936 has 10 divisors (see below), whose sum is σ = 41063282. Its totient is φ = 10596960.

The previous prime is 21193927. The next prime is 21193937. The reversal of 21193936 is 63939112.

It can be written as a sum of positive squares in only one way, i.e., 16353936 + 4840000 = 4044^2 + 2200^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21193937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 662295 + ... + 662326.

Almost surely, 2^21193936 is an apocalyptic number.

It is an amenable number.

21193936 is a deficient number, since it is larger than the sum of its proper divisors (19869346).

21193936 is a wasteful number, since it uses less digits than its factorization.

21193936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1324629 (or 1324623 counting only the distinct ones).

The product of its digits is 8748, while the sum is 34.

The square root of 21193936 is about 4603.6872178722. The cubic root of 21193936 is about 276.7391097534.

The spelling of 21193936 in words is "twenty-one million, one hundred ninety-three thousand, nine hundred thirty-six".