74202721 has 4 divisors (see below), whose sum is σ = 74333700. Its totient is φ = 74071744.

The previous prime is 74202719. The next prime is 74202727. The reversal of 74202721 is 12720247.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 31809600 + 42393121 = 5640^2 + 6511^2 .

It is a cyclic number.

It is not a de Polignac number, because 74202721 - 2¹ = 74202719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (74202727) 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 in 3 ways as a sum of consecutive naturals, for example, 64636 + ... + 65773.

It is an arithmetic number, because the mean of its divisors is an integer number (18583425).

Almost surely, 2^74202721 is an apocalyptic number.

It is an amenable number.

74202721 is a deficient number, since it is larger than the sum of its proper divisors (130979).

74202721 is a wasteful number, since it uses less digits than its factorization.

74202721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130978.

The product of its (nonzero) digits is 1568, while the sum is 25.

The square root of 74202721 is about 8614.1001271172. The cubic root of 74202721 is about 420.2166701397.

Adding to 74202721 its reverse (12720247), we get a palindrome (86922968).

The spelling of 74202721 in words is "seventy-four million, two hundred two thousand, seven hundred twenty-one".