21339237 has 8 divisors (see below), whose sum is σ = 28597536. Its totient is φ = 14153552.

The previous prime is 21339221. The next prime is 21339247. The reversal of 21339237 is 73293312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21339237 - 2⁴ = 21339221 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21339247) 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, 17463 + ... + 18644.

It is an arithmetic number, because the mean of its divisors is an integer number (3574692).

Almost surely, 2^21339237 is an apocalyptic number.

It is an amenable number.

21339237 is a deficient number, since it is larger than the sum of its proper divisors (7258299).

21339237 is a wasteful number, since it uses less digits than its factorization.

21339237 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36307.

The product of its digits is 6804, while the sum is 30.

The square root of 21339237 is about 4619.4411999721. The cubic root of 21339237 is about 277.3700909672.

The spelling of 21339237 in words is "twenty-one million, three hundred thirty-nine thousand, two hundred thirty-seven".