21713838 has 16 divisors (see below), whose sum is σ = 43876560. Its totient is φ = 7163136.

The previous prime is 21713833. The next prime is 21713843. The reversal of 21713838 is 83831712.

It is an interprime number because it is at equal distance from previous prime (21713833) and next prime (21713843).

It is a junction number, because it is equal to n+sod(n) for n = 21713799 and 21713808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21713833) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18073 + ... + 19236.

It is an arithmetic number, because the mean of its divisors is an integer number (2742285).

Almost surely, 2^21713838 is an apocalyptic number.

21713838 is an abundant number, since it is smaller than the sum of its proper divisors (22162722).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21713838 is a wasteful number, since it uses less digits than its factorization.

21713838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37411.

The product of its digits is 8064, while the sum is 33.

The square root of 21713838 is about 4659.8109403709. The cubic root of 21713838 is about 278.9837222810.

The spelling of 21713838 in words is "twenty-one million, seven hundred thirteen thousand, eight hundred thirty-eight".