81051219080 has 32 divisors (see below), whose sum is σ = 196393339800. Its totient is φ = 29926603776.

The previous prime is 81051219077. The next prime is 81051219091. The reversal of 81051219080 is 8091215018.

It can be written as a sum of positive squares in 4 ways, for example, as 56665898116 + 24385320964 = 238046^2 + 156158^2 .

It is a super-2 number, since 2×81051219080² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81051219080.

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, 77933345 + ... + 77934384.

Almost surely, 2^81051219080 is an apocalyptic number.

It is an amenable number.

81051219080 is an abundant number, since it is smaller than the sum of its proper divisors (115342120720).

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

81051219080 is a wasteful number, since it uses less digits than its factorization.

81051219080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155867753 (or 155867749 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 35.

The spelling of 81051219080 in words is "eighty-one billion, fifty-one million, two hundred nineteen thousand, eighty".