74921221 has 2 divisors, whose sum is σ = 74921222. Its totient is φ = 74921220.

The previous prime is 74921219. The next prime is 74921257. The reversal of 74921221 is 12212947.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37576900 + 37344321 = 6130^2 + 6111^2 .

It is a cyclic number.

It is not a de Polignac number, because 74921221 - 2¹ = 74921219 is a prime.

It is a super-2 number, since 2×74921221² = 11226378712261682, which contains 22 as substring.

Together with 74921219, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 74921221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (74921291) 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, 37460610 + 37460611.

It is an arithmetic number, because the mean of its divisors is an integer number (37460611).

Almost surely, 2^74921221 is an apocalyptic number.

It is an amenable number.

74921221 is a deficient number, since it is larger than the sum of its proper divisors (1).

74921221 is an equidigital number, since it uses as much as digits as its factorization.

74921221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 28.

The square root of 74921221 is about 8655.7045351606. The cubic root of 74921221 is about 421.5686258514.

The spelling of 74921221 in words is "seventy-four million, nine hundred twenty-one thousand, two hundred twenty-one".