821142720 has 84 divisors (see below), whose sum is σ = 2824398720. Its totient is φ = 218970624.

The previous prime is 821142719. The next prime is 821142731. The reversal of 821142720 is 27241128.

821142720 is a `hidden beast` number, since 8 + 211 + 427 + 20 = 666.

821142720 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 139680 + ... + 145439.

Almost surely, 2^821142720 is an apocalyptic number.

821142720 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

821142720 is an abundant number, since it is smaller than the sum of its proper divisors (2003256000).

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

821142720 is a wasteful number, since it uses less digits than its factorization.

821142720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285142 (or 285129 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 821142720 is about 28655.5879367358. The cubic root of 821142720 is about 936.4247469578.

Adding to 821142720 its reverse (27241128), we get a palindrome (848383848).

The spelling of 821142720 in words is "eight hundred twenty-one million, one hundred forty-two thousand, seven hundred twenty".