21130073 has 2 divisors, whose sum is σ = 21130074. Its totient is φ = 21130072.

The previous prime is 21130049. The next prime is 21130079. The reversal of 21130073 is 37003112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15784729 + 5345344 = 3973^2 + 2312^2 .

It is a cyclic number.

It is not a de Polignac number, because 21130073 - 2¹⁰ = 21129049 is a prime.

It is not a weakly prime, because it can be changed into another prime (21130079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565036 + 10565037.

It is an arithmetic number, because the mean of its divisors is an integer number (10565037).

Almost surely, 2^21130073 is an apocalyptic number.

It is an amenable number.

21130073 is a deficient number, since it is larger than the sum of its proper divisors (1).

21130073 is an equidigital number, since it uses as much as digits as its factorization.

21130073 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 126, while the sum is 17.

The square root of 21130073 is about 4596.7459142311. The cubic root of 21130073 is about 276.4608670980.

Adding to 21130073 its reverse (37003112), we get a palindrome (58133185).

The spelling of 21130073 in words is "twenty-one million, one hundred thirty thousand, seventy-three".