747644221 has 4 divisors (see below), whose sum is σ = 747698944. Its totient is φ = 747589500.

The previous prime is 747644171. The next prime is 747644257. The reversal of 747644221 is 122446747.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 747644221 - 2¹⁵ = 747611453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (747644021) 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, 12196 + ... + 40546.

It is an arithmetic number, because the mean of its divisors is an integer number (186924736).

Almost surely, 2^747644221 is an apocalyptic number.

It is an amenable number.

747644221 is a deficient number, since it is larger than the sum of its proper divisors (54723).

747644221 is a wasteful number, since it uses less digits than its factorization.

747644221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54722.

The product of its digits is 75264, while the sum is 37.

The square root of 747644221 is about 27343.0836044511. The cubic root of 747644221 is about 907.6080243372.

The spelling of 747644221 in words is "seven hundred forty-seven million, six hundred forty-four thousand, two hundred twenty-one".