81355619020 has 48 divisors (see below), whose sum is σ = 188267698080. Its totient is φ = 29340412416.

The previous prime is 81355619011. The next prime is 81355619039. The reversal of 81355619020 is 2091655318.

It is a super-2 number, since 2×81355619020² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3627265 + ... + 3649624.

It is an arithmetic number, because the mean of its divisors is an integer number (3922243710).

Almost surely, 2^81355619020 is an apocalyptic number.

It is an amenable number.

81355619020 is an abundant number, since it is smaller than the sum of its proper divisors (106912079060).

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

81355619020 is a wasteful number, since it uses less digits than its factorization.

81355619020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7276954 (or 7276952 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 40.

The spelling of 81355619020 in words is "eighty-one billion, three hundred fifty-five million, six hundred nineteen thousand, twenty".