21365047 has 8 divisors (see below), whose sum is σ = 23371920. Its totient is φ = 19368960.

The previous prime is 21365041. The next prime is 21365077. The reversal of 21365047 is 74056312.

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 21365047 - 2⁷ = 21364919 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21365041) 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, 1783 + ... + 6775.

It is an arithmetic number, because the mean of its divisors is an integer number (2921490).

Almost surely, 2^21365047 is an apocalyptic number.

21365047 is a deficient number, since it is larger than the sum of its proper divisors (2006873).

21365047 is a wasteful number, since it uses less digits than its factorization.

21365047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5393.

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 21365047 is about 4622.2339836923. The cubic root of 21365047 is about 277.4818731227.

The spelling of 21365047 in words is "twenty-one million, three hundred sixty-five thousand, forty-seven".