21993735 has 16 divisors (see below), whose sum is σ = 37042560. Its totient is φ = 11112480.

The previous prime is 21993707. The next prime is 21993757. The reversal of 21993735 is 53739912.

It is not a de Polignac number, because 21993735 - 2⁵ = 21993703 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21993693 and 21993702.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38301 + ... + 38870.

It is an arithmetic number, because the mean of its divisors is an integer number (2315160).

Almost surely, 2^21993735 is an apocalyptic number.

21993735 is a deficient number, since it is larger than the sum of its proper divisors (15048825).

21993735 is a wasteful number, since it uses less digits than its factorization.

21993735 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77198.

The product of its digits is 51030, while the sum is 39.

The square root of 21993735 is about 4689.7478610262. The cubic root of 21993735 is about 280.1773323943.

The spelling of 21993735 in words is "twenty-one million, nine hundred ninety-three thousand, seven hundred thirty-five".