821712069 has 24 divisors (see below), whose sum is σ = 1216378592. Its totient is φ = 534250080.

The previous prime is 821711999. The next prime is 821712077. The reversal of 821712069 is 960217128.

821712069 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 821712069 - 2⁷ = 821711941 is a prime.

It is a super-2 number, since 2×821712069² = 1350421448680521522, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821712469) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 349839 + ... + 352179.

Almost surely, 2^821712069 is an apocalyptic number.

It is an amenable number.

821712069 is a deficient number, since it is larger than the sum of its proper divisors (394666523).

821712069 is a wasteful number, since it uses less digits than its factorization.

821712069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3297 (or 3294 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 821712069 is about 28665.5205604224. The cubic root of 821712069 is about 936.6411240078.

The spelling of 821712069 in words is "eight hundred twenty-one million, seven hundred twelve thousand, sixty-nine".