21739361 has 8 divisors (see below), whose sum is σ = 24945984. Its totient is φ = 18558000.

The previous prime is 21739351. The next prime is 21739369. The reversal of 21739361 is 16393712.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21739361 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21739369) 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, 4430 + ... + 7943.

It is an arithmetic number, because the mean of its divisors is an integer number (3118248).

Almost surely, 2^21739361 is an apocalyptic number.

It is an amenable number.

21739361 is a deficient number, since it is larger than the sum of its proper divisors (3206623).

21739361 is a wasteful number, since it uses less digits than its factorization.

21739361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12631.

The product of its digits is 6804, while the sum is 32.

The square root of 21739361 is about 4662.5487665010. The cubic root of 21739361 is about 279.0929876796.

The spelling of 21739361 in words is "twenty-one million, seven hundred thirty-nine thousand, three hundred sixty-one".