745422721 has 4 divisors (see below), whose sum is σ = 746105812. Its totient is φ = 744739632.

The previous prime is 745422719. The next prime is 745422737. The reversal of 745422721 is 127224547.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127224547 = 953 ⋅133499.

It can be written as a sum of positive squares in 2 ways, for example, as 719044225 + 26378496 = 26815^2 + 5136^2 .

It is a cyclic number.

It is not a de Polignac number, because 745422721 - 2¹ = 745422719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (745422701) 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, 339906 + ... + 342091.

It is an arithmetic number, because the mean of its divisors is an integer number (186526453).

Almost surely, 2^745422721 is an apocalyptic number.

It is an amenable number.

745422721 is a deficient number, since it is larger than the sum of its proper divisors (683091).

745422721 is a wasteful number, since it uses less digits than its factorization.

745422721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 683090.

The product of its digits is 31360, while the sum is 34.

The square root of 745422721 is about 27302.4306793370. The cubic root of 745422721 is about 906.7081972728.

The spelling of 745422721 in words is "seven hundred forty-five million, four hundred twenty-two thousand, seven hundred twenty-one".