21366037 has 16 divisors (see below), whose sum is σ = 27500544. Its totient is φ = 16110000.

The previous prime is 21366017. The next prime is 21366041. The reversal of 21366037 is 73066312.

It is a cyclic number.

It is not a de Polignac number, because 21366037 - 2¹¹ = 21363989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21365996 and 21366014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21366017) 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, 2089 + ... + 6862.

It is an arithmetic number, because the mean of its divisors is an integer number (1718784).

Almost surely, 2^21366037 is an apocalyptic number.

It is an amenable number.

21366037 is a deficient number, since it is larger than the sum of its proper divisors (6134507).

21366037 is a wasteful number, since it uses less digits than its factorization.

21366037 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9000.

The product of its (nonzero) digits is 4536, while the sum is 28.

The square root of 21366037 is about 4622.3410735254. The cubic root of 21366037 is about 277.4861589828.

The spelling of 21366037 in words is "twenty-one million, three hundred sixty-six thousand, thirty-seven".