21500853 has 24 divisors (see below), whose sum is σ = 32060448. Its totient is φ = 12804000.

The previous prime is 21500833. The next prime is 21500893. The reversal of 21500853 is 35800512.

It is not a de Polignac number, because 21500853 - 2⁵ = 21500821 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21500813) 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 in 23 ways as a sum of consecutive naturals, for example, 21658 + ... + 22628.

It is an arithmetic number, because the mean of its divisors is an integer number (1335852).

Almost surely, 2^21500853 is an apocalyptic number.

It is an amenable number.

21500853 is a deficient number, since it is larger than the sum of its proper divisors (10559595).

21500853 is a wasteful number, since it uses less digits than its factorization.

21500853 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1057 (or 1046 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 21500853 is about 4636.9012281911. The cubic root of 21500853 is about 278.0685656317.

The spelling of 21500853 in words is "twenty-one million, five hundred thousand, eight hundred fifty-three".