820749 has 8 divisors (see below), whose sum is σ = 1113120. Its totient is φ = 537776.

The previous prime is 820747. The next prime is 820753. The reversal of 820749 is 947028.

820749 is nontrivially palindromic in base 7.

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

It is a cyclic number.

It is not a de Polignac number, because 820749 - 2¹ = 820747 is a prime.

820749 is a lucky number.

It is a zygodrome in base 7.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 820749.

It is not an unprimeable number, because it can be changed into a prime (820747) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2142 + ... + 2495.

It is an arithmetic number, because the mean of its divisors is an integer number (139140).

2⁸²⁰⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

820749 is a deficient number, since it is larger than the sum of its proper divisors (292371).

820749 is a wasteful number, since it uses less digits than its factorization.

820749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4699.

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 820749 is about 905.9519854827. The cubic root of 820749 is about 93.6275057960.

It can be divided in two parts, 8207 and 49, that added together give a triangular number (8256 = T₁₂₈).

The spelling of 820749 in words is "eight hundred twenty thousand, seven hundred forty-nine".