745521 has 16 divisors (see below), whose sum is σ = 1148928. Its totient is φ = 421200.

The previous prime is 745517. The next prime is 745529. The reversal of 745521 is 125547.

It is not a de Polignac number, because 745521 - 2² = 745517 is a prime.

It is a super-2 number, since 2×745521² = 1111603122882, which contains 22 as substring.

745521 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 745491 and 745500.

It is not an unprimeable number, because it can be changed into a prime (745529) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2616 + ... + 2886.

It is an arithmetic number, because the mean of its divisors is an integer number (71808).

2⁷⁴⁵⁵²¹ is an apocalyptic number.

It is an amenable number.

745521 is a deficient number, since it is larger than the sum of its proper divisors (403407).

745521 is a wasteful number, since it uses less digits than its factorization.

745521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412.

The product of its digits is 1400, while the sum is 24.

The square root of 745521 is about 863.4355795310. The cubic root of 745521 is about 90.6748043325.

The spelling of 745521 in words is "seven hundred forty-five thousand, five hundred twenty-one".