745543621 has 4 divisors (see below), whose sum is σ = 748799500. Its totient is φ = 742287744.

The previous prime is 745543613. The next prime is 745543627. The reversal of 745543621 is 126345547.

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 454158721 + 291384900 = 21311^2 + 17070^2 .

It is a cyclic number.

It is not a de Polignac number, because 745543621 - 2³ = 745543613 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 (745543627) 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, 1627596 + ... + 1628053.

It is an arithmetic number, because the mean of its divisors is an integer number (187199875).

Almost surely, 2^745543621 is an apocalyptic number.

It is an amenable number.

745543621 is a deficient number, since it is larger than the sum of its proper divisors (3255879).

745543621 is a wasteful number, since it uses less digits than its factorization.

745543621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3255878.

The product of its digits is 100800, while the sum is 37.

The square root of 745543621 is about 27304.6446781495. The cubic root of 745543621 is about 906.7572142454.

It can be divided in two parts, 7455 and 43621, that added together give a square (51076 = 226²).

The spelling of 745543621 in words is "seven hundred forty-five million, five hundred forty-three thousand, six hundred twenty-one".