821542080 has 224 divisors, whose sum is σ = 2717231040. Its totient is φ = 210124800.

The previous prime is 821542079. The next prime is 821542087. The reversal of 821542080 is 80245128.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (821542087) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3587406 + ... + 3587634.

Almost surely, 2^821542080 is an apocalyptic number.

821542080 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821542080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1358615520).

821542080 is an abundant number, since it is smaller than the sum of its proper divisors (1895688960).

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

821542080 is a wasteful number, since it uses less digits than its factorization.

821542080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 387 (or 377 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 30.

The square root of 821542080 is about 28662.5553640983. Note that the first 3 decimals coincide. The cubic root of 821542080 is about 936.5765313625.

The spelling of 821542080 in words is "eight hundred twenty-one million, five hundred forty-two thousand, eighty".