21738807 has 16 divisors (see below), whose sum is σ = 32335360. Its totient is φ = 14434200.

The previous prime is 21738803. The next prime is 21738809. The reversal of 21738807 is 70883712.

It is not a de Polignac number, because 21738807 - 2² = 21738803 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21738803) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5832 + ... + 8802.

It is an arithmetic number, because the mean of its divisors is an integer number (2020960).

Almost surely, 2^21738807 is an apocalyptic number.

21738807 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21738807 is a deficient number, since it is larger than the sum of its proper divisors (10596553).

21738807 is a wasteful number, since it uses less digits than its factorization.

21738807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3251 (or 3245 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 21738807 is about 4662.4893565562. The cubic root of 21738807 is about 279.0906168827.

The spelling of 21738807 in words is "twenty-one million, seven hundred thirty-eight thousand, eight hundred seven".