731443021 has 2 divisors, whose sum is σ = 731443022. Its totient is φ = 731443020.

The previous prime is 731442997. The next prime is 731443039. The reversal of 731443021 is 120344137.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 676520100 + 54922921 = 26010^2 + 7411^2 .

It is a cyclic number.

It is not a de Polignac number, because 731443021 - 2⁷ = 731442893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (731443051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 365721510 + 365721511.

It is an arithmetic number, because the mean of its divisors is an integer number (365721511).

Almost surely, 2^731443021 is an apocalyptic number.

It is an amenable number.

731443021 is a deficient number, since it is larger than the sum of its proper divisors (1).

731443021 is an equidigital number, since it uses as much as digits as its factorization.

731443021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 25.

The square root of 731443021 is about 27045.2032900476. The cubic root of 731443021 is about 901.0042374718.

Adding to 731443021 its reverse (120344137), we get a palindrome (851787158).

The spelling of 731443021 in words is "seven hundred thirty-one million, four hundred forty-three thousand, twenty-one".