821237040 has 120 divisors (see below), whose sum is σ = 2970174480. Its totient is φ = 202148352.

The previous prime is 821236987. The next prime is 821237041. The reversal of 821237040 is 40732128.

It is a tau number, because it is divible by the number of its divisors (120).

It is a junction number, because it is equal to n+sod(n) for n = 821236995 and 821237013.

It is not an unprimeable number, because it can be changed into a prime (821237041) 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 23 ways as a sum of consecutive naturals, for example, 34510 + ... + 53229.

It is an arithmetic number, because the mean of its divisors is an integer number (24751454).

Almost surely, 2^821237040 is an apocalyptic number.

821237040 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

821237040 is an abundant number, since it is smaller than the sum of its proper divisors (2148937440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

821237040 is a wasteful number, since it uses less digits than its factorization.

821237040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87771 (or 87762 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 821237040 is about 28657.2336417875. The cubic root of 821237040 is about 936.4605995156.

Adding to 821237040 its reverse (40732128), we get a palindrome (861969168).

The spelling of 821237040 in words is "eight hundred twenty-one million, two hundred thirty-seven thousand, forty".