21458936 has 16 divisors (see below), whose sum is σ = 40554240. Its totient is φ = 10644480.

The previous prime is 21458933. The next prime is 21458953. The reversal of 21458936 is 63985412.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21458936.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21458933) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9545 + ... + 11576.

It is an arithmetic number, because the mean of its divisors is an integer number (2534640).

Almost surely, 2^21458936 is an apocalyptic number.

It is an amenable number.

21458936 is a deficient number, since it is larger than the sum of its proper divisors (19095304).

21458936 is a wasteful number, since it uses less digits than its factorization.

21458936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21254 (or 21250 counting only the distinct ones).

The product of its digits is 51840, while the sum is 38.

The square root of 21458936 is about 4632.3790863875. The cubic root of 21458936 is about 277.8877451653.

The spelling of 21458936 in words is "twenty-one million, four hundred fifty-eight thousand, nine hundred thirty-six".