21947093 has 4 divisors (see below), whose sum is σ = 25082400. Its totient is φ = 18811788.

The previous prime is 21947089. The next prime is 21947099. The reversal of 21947093 is 39074912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21947093 - 2² = 21947089 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21947099) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1567643 + ... + 1567656.

It is an arithmetic number, because the mean of its divisors is an integer number (6270600).

Almost surely, 2^21947093 is an apocalyptic number.

It is an amenable number.

21947093 is a deficient number, since it is larger than the sum of its proper divisors (3135307).

21947093 is an equidigital number, since it uses as much as digits as its factorization.

21947093 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3135306.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 21947093 is about 4684.7724597893. The cubic root of 21947093 is about 279.9791353500.

The spelling of 21947093 in words is "twenty-one million, nine hundred forty-seven thousand, ninety-three".