21179047 has 2 divisors, whose sum is σ = 21179048. Its totient is φ = 21179046.

The previous prime is 21179033. The next prime is 21179051. The reversal of 21179047 is 74097112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21179047 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21179747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10589523 + 10589524.

It is an arithmetic number, because the mean of its divisors is an integer number (10589524).

Almost surely, 2^21179047 is an apocalyptic number.

21179047 is a deficient number, since it is larger than the sum of its proper divisors (1).

21179047 is an equidigital number, since it uses as much as digits as its factorization.

21179047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3528, while the sum is 31.

The square root of 21179047 is about 4602.0698603998. The cubic root of 21179047 is about 276.6742903659.

The spelling of 21179047 in words is "twenty-one million, one hundred seventy-nine thousand, forty-seven".