74747221 has 2 divisors, whose sum is σ = 74747222. Its totient is φ = 74747220.

The previous prime is 74747209. The next prime is 74747243. The reversal of 74747221 is 12274747.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65836996 + 8910225 = 8114^2 + 2985^2 .

It is a cyclic number.

It is not a de Polignac number, because 74747221 - 2⁷ = 74747093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (74747251) 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, 37373610 + 37373611.

It is an arithmetic number, because the mean of its divisors is an integer number (37373611).

Almost surely, 2^74747221 is an apocalyptic number.

It is an amenable number.

74747221 is a deficient number, since it is larger than the sum of its proper divisors (1).

74747221 is an equidigital number, since it uses as much as digits as its factorization.

74747221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21952, while the sum is 34.

The square root of 74747221 is about 8645.6475176819. The cubic root of 74747221 is about 421.2420170072.

The spelling of 74747221 in words is "seventy-four million, seven hundred forty-seven thousand, two hundred twenty-one".