745330021 has 4 divisors (see below), whose sum is σ = 763508844. Its totient is φ = 727151200.

The previous prime is 745330013. The next prime is 745330037. The reversal of 745330021 is 120033547.

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 395452996 + 349877025 = 19886^2 + 18705^2 .

It is a cyclic number.

It is not a de Polignac number, because 745330021 - 2³ = 745330013 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 (745330921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9089350 + ... + 9089431.

It is an arithmetic number, because the mean of its divisors is an integer number (190877211).

Almost surely, 2^745330021 is an apocalyptic number.

It is an amenable number.

745330021 is a deficient number, since it is larger than the sum of its proper divisors (18178823).

745330021 is a wasteful number, since it uses less digits than its factorization.

745330021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18178822.

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 745330021 is about 27300.7329755082. The cubic root of 745330021 is about 906.6706099496.

Adding to 745330021 its reverse (120033547), we get a palindrome (865363568).

The spelling of 745330021 in words is "seven hundred forty-five million, three hundred thirty thousand, twenty-one".