749521 has 8 divisors (see below), whose sum is σ = 779688. Its totient is φ = 720000.

The previous prime is 749471. The next prime is 749543. The reversal of 749521 is 125947.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3025 + 746496 = 55^2 + 864^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a 4-Lehmer number, since φ(749521) divides (749521-1)⁴.

It is a cyclic number.

It is not a de Polignac number, because 749521 - 2⁷ = 749393 is a prime.

It is a deceptive number, since it divides R₇₄₉₅₂₀.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 749521.

It is not an unprimeable number, because it can be changed into a prime (740521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4051 + ... + 4231.

It is an arithmetic number, because the mean of its divisors is an integer number (97461).

2⁷⁴⁹⁵²¹ is an apocalyptic number.

It is an amenable number.

749521 is a deficient number, since it is larger than the sum of its proper divisors (30167).

749521 is a wasteful number, since it uses less digits than its factorization.

749521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323.

The product of its digits is 2520, while the sum is 28.

The square root of 749521 is about 865.7488088354. The cubic root of 749521 is about 90.8366832832.

The spelling of 749521 in words is "seven hundred forty-nine thousand, five hundred twenty-one".