820147487544 has 640 divisors, whose sum is σ = 2983317765120. Its totient is φ = 204315955200.

The previous prime is 820147487449. The next prime is 820147487587. The reversal of 820147487544 is 445784741028.

It is a happy number.

820147487544 is a `hidden beast` number, since 8 + 2 + 0 + 14 + 7 + 4 + 87 + 544 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 131073664 + ... + 131079920.

It is an arithmetic number, because the mean of its divisors is an integer number (4661434008).

Almost surely, 2^820147487544 is an apocalyptic number.

820147487544 is a gapful number since it is divisible by the number (84) 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 820147487544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1491658882560).

820147487544 is an abundant number, since it is smaller than the sum of its proper divisors (2163170277576).

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

820147487544 is a wasteful number, since it uses less digits than its factorization.

820147487544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6401 (or 6388 counting only the distinct ones).

The product of its (nonzero) digits is 8028160, while the sum is 54.

The spelling of 820147487544 in words is "eight hundred twenty billion, one hundred forty-seven million, four hundred eighty-seven thousand, five hundred forty-four".