821275389 has 128 divisors (see below), whose sum is σ = 1492992000. Its totient is φ = 440294400.

The previous prime is 821275319. The next prime is 821275417. The reversal of 821275389 is 983572128.

It is a happy number.

It is not a de Polignac number, because 821275389 - 2⁷ = 821275261 is a prime.

Its product of digits (241920) is a multiple of the sum of its prime divisors (210).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821275309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 10395852 + ... + 10395930.

It is an arithmetic number, because the mean of its divisors is an integer number (11664000).

Almost surely, 2^821275389 is an apocalyptic number.

It is an amenable number.

821275389 is a deficient number, since it is larger than the sum of its proper divisors (671716611).

821275389 is a wasteful number, since it uses less digits than its factorization.

821275389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216 (or 210 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 821275389 is about 28657.9027320563. The cubic root of 821275389 is about 936.4751758059.

The spelling of 821275389 in words is "eight hundred twenty-one million, two hundred seventy-five thousand, three hundred eighty-nine".