73971221 has 2 divisors, whose sum is σ = 73971222. Its totient is φ = 73971220.

The previous prime is 73971203. The next prime is 73971241. The reversal of 73971221 is 12217937.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56415121 + 17556100 = 7511^2 + 4190^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-73971221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (73971241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36985610 + 36985611.

It is an arithmetic number, because the mean of its divisors is an integer number (36985611).

Almost surely, 2^73971221 is an apocalyptic number.

It is an amenable number.

73971221 is a deficient number, since it is larger than the sum of its proper divisors (1).

73971221 is an equidigital number, since it uses as much as digits as its factorization.

73971221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5292, while the sum is 32.

The square root of 73971221 is about 8600.6523589784. The cubic root of 73971221 is about 419.7792131325.

The spelling of 73971221 in words is "seventy-three million, nine hundred seventy-one thousand, two hundred twenty-one".