745471621 has 4 divisors (see below), whose sum is σ = 747294700. Its totient is φ = 743648544.

The previous prime is 745471619. The next prime is 745471627. The reversal of 745471621 is 126174547.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 126174547 = 1559 ⋅80933.

It can be written as a sum of positive squares in 2 ways, for example, as 726895521 + 18576100 = 26961^2 + 4310^2 .

It is a cyclic number.

It is not a de Polignac number, because 745471621 - 2¹ = 745471619 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 (745471627) 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, 910926 + ... + 911743.

It is an arithmetic number, because the mean of its divisors is an integer number (186823675).

Almost surely, 2^745471621 is an apocalyptic number.

It is an amenable number.

745471621 is a deficient number, since it is larger than the sum of its proper divisors (1823079).

745471621 is a wasteful number, since it uses less digits than its factorization.

745471621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1823078.

The product of its digits is 47040, while the sum is 37.

The square root of 745471621 is about 27303.3261893125. The cubic root of 745471621 is about 906.7280236345.

The spelling of 745471621 in words is "seven hundred forty-five million, four hundred seventy-one thousand, six hundred twenty-one".