8537821820 has 24 divisors (see below), whose sum is σ = 19559374128. Its totient is φ = 3104662400.

The previous prime is 8537821819. The next prime is 8537821841. The reversal of 8537821820 is 281287358.

It is a super-2 number, since 2×8537821820² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19403921 + ... + 19404360.

It is an arithmetic number, because the mean of its divisors is an integer number (814973922).

Almost surely, 2^8537821820 is an apocalyptic number.

It is an amenable number.

8537821820 is an abundant number, since it is smaller than the sum of its proper divisors (11021552308).

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

8537821820 is a wasteful number, since it uses less digits than its factorization.

8537821820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38808301 (or 38808299 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 44.

The square root of 8537821820 is about 92400.3345232040. The cubic root of 8537821820 is about 2043.8500454225.

The spelling of 8537821820 in words is "eight billion, five hundred thirty-seven million, eight hundred twenty-one thousand, eight hundred twenty".