21730799 has 2 divisors, whose sum is σ = 21730800. Its totient is φ = 21730798.

The previous prime is 21730769. The next prime is 21730817. The reversal of 21730799 is 99703712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21730799 - 2⁸ = 21730543 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 (21730739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10865399 + 10865400.

It is an arithmetic number, because the mean of its divisors is an integer number (10865400).

Almost surely, 2^21730799 is an apocalyptic number.

21730799 is a deficient number, since it is larger than the sum of its proper divisors (1).

21730799 is an equidigital number, since it uses as much as digits as its factorization.

21730799 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23814, while the sum is 38.

The square root of 21730799 is about 4661.6305087383. The cubic root of 21730799 is about 279.0563428131.

The spelling of 21730799 in words is "twenty-one million, seven hundred thirty thousand, seven hundred ninety-nine".