745758721 has 4 divisors (see below), whose sum is σ = 785009200. Its totient is φ = 706508244.

The previous prime is 745758719. The next prime is 745758731. The reversal of 745758721 is 127857547.

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 an emirpimes, since its reverse is a distinct semiprime: 127857547 = 31 ⋅4124437.

It is a cyclic number.

It is not a de Polignac number, because 745758721 - 2¹ = 745758719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (745758701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19625211 + ... + 19625248.

It is an arithmetic number, because the mean of its divisors is an integer number (196252300).

Almost surely, 2^745758721 is an apocalyptic number.

It is an amenable number.

745758721 is a deficient number, since it is larger than the sum of its proper divisors (39250479).

745758721 is a wasteful number, since it uses less digits than its factorization.

745758721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39250478.

The product of its digits is 548800, while the sum is 46.

The square root of 745758721 is about 27308.5832843815. The cubic root of 745758721 is about 906.8444100028.

The spelling of 745758721 in words is "seven hundred forty-five million, seven hundred fifty-eight thousand, seven hundred twenty-one".