21999073 has 2 divisors, whose sum is σ = 21999074. Its totient is φ = 21999072.

The previous prime is 21999059. The next prime is 21999079. The reversal of 21999073 is 37099912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21790224 + 208849 = 4668^2 + 457^2 .

It is a cyclic number.

It is not a de Polignac number, because 21999073 - 2⁵ = 21999041 is a prime.

It is not a weakly prime, because it can be changed into another prime (21999079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10999536 + 10999537.

It is an arithmetic number, because the mean of its divisors is an integer number (10999537).

Almost surely, 2^21999073 is an apocalyptic number.

It is an amenable number.

21999073 is a deficient number, since it is larger than the sum of its proper divisors (1).

21999073 is an equidigital number, since it uses as much as digits as its factorization.

21999073 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30618, while the sum is 40.

The square root of 21999073 is about 4690.3169402504. The cubic root of 21999073 is about 280.1999974187.

The spelling of 21999073 in words is "twenty-one million, nine hundred ninety-nine thousand, seventy-three".