731552221 has 2 divisors, whose sum is σ = 731552222. Its totient is φ = 731552220.

The previous prime is 731552203. The next prime is 731552281. The reversal of 731552221 is 122255137.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 662496121 + 69056100 = 25739^2 + 8310^2 .

It is an emirp because it is prime and its reverse (122255137) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-731552221 is a prime.

It is a super-3 number, since 3×731552221³ (a number of 28 digits) contains 333 as substring.

It is a Chen prime.

It is equal to p_37800217 and since 731552221 and 37800217 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 731552221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (731552281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 365776110 + 365776111.

It is an arithmetic number, because the mean of its divisors is an integer number (365776111).

Almost surely, 2^731552221 is an apocalyptic number.

It is an amenable number.

731552221 is a deficient number, since it is larger than the sum of its proper divisors (1).

731552221 is an equidigital number, since it uses as much as digits as its factorization.

731552221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4200, while the sum is 28.

The square root of 731552221 is about 27047.2220569877. Note that the first 3 decimals coincide. The cubic root of 731552221 is about 901.0490733938.

It can be divided in two parts, 7315 and 52221, that added together give a square (59536 = 244²).

The spelling of 731552221 in words is "seven hundred thirty-one million, five hundred fifty-two thousand, two hundred twenty-one".