73690021 has 2 divisors, whose sum is σ = 73690022. Its totient is φ = 73690020.

The previous prime is 73690009. The next prime is 73690061. The reversal of 73690021 is 12009637.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60621796 + 13068225 = 7786^2 + 3615^2 .

It is an emirp because it is prime and its reverse (12009637) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 73690021 - 2¹¹ = 73687973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (73690061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36845010 + 36845011.

It is an arithmetic number, because the mean of its divisors is an integer number (36845011).

Almost surely, 2^73690021 is an apocalyptic number.

It is an amenable number.

73690021 is a deficient number, since it is larger than the sum of its proper divisors (1).

73690021 is an equidigital number, since it uses as much as digits as its factorization.

73690021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2268, while the sum is 28.

The square root of 73690021 is about 8584.2891959672. The cubic root of 73690021 is about 419.2466104628.

Adding to 73690021 its reverse (12009637), we get a palindrome (85699658).

The spelling of 73690021 in words is "seventy-three million, six hundred ninety thousand, twenty-one".