21738107 has 4 divisors (see below), whose sum is σ = 21764160. Its totient is φ = 21712056.

The previous prime is 21738103. The next prime is 21738113. The reversal of 21738107 is 70183712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21738107 - 2² = 21738103 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21738107.

It is not an unprimeable number, because it can be changed into a prime (21738103) 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, 11732 + ... + 13457.

It is an arithmetic number, because the mean of its divisors is an integer number (5441040).

Almost surely, 2^21738107 is an apocalyptic number.

21738107 is a deficient number, since it is larger than the sum of its proper divisors (26053).

21738107 is an equidigital number, since it uses as much as digits as its factorization.

21738107 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26052.

The product of its (nonzero) digits is 2352, while the sum is 29.

The square root of 21738107 is about 4662.4142887564. The cubic root of 21738107 is about 279.0876212334.

The spelling of 21738107 in words is "twenty-one million, seven hundred thirty-eight thousand, one hundred seven".