405769 has 15 divisors (see below), whose sum is σ = 512583. Its totient is φ = 321048.

The previous prime is 405767. The next prime is 405781. The reversal of 405769 is 967504.

The square root of 405769 is 637.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 60025 + 345744 = 245^2 + 588^2 .

It is not a de Polignac number, because 405769 - 2¹ = 405767 is a prime.

It is a super-2 number, since 2×405769² = 329296962722, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a nialpdrome in base 7.

It is a self number, because there is not a number n which added to its sum of digits gives 405769.

It is not an unprimeable number, because it can be changed into a prime (405763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 31207 + ... + 31219.

2⁴⁰⁵⁷⁶⁹ is an apocalyptic number.

405769 is a gapful number since it is divisible by the number (49) formed by its first and last digit.

405769 is the 637-th square number.

405769 is the 319-th centered octagonal number.

It is an amenable number.

405769 is a deficient number, since it is larger than the sum of its proper divisors (106814).

405769 is an frugal number, since it uses more digits than its factorization.

405769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54 (or 20 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 31.

The cubic root of 405769 is about 74.0331602053.

The spelling of 405769 in words is "four hundred five thousand, seven hundred sixty-nine".