81161086722 has 16 divisors (see below), whose sum is σ = 162393363552. Its totient is φ = 27041830560.

The previous prime is 81161086709. The next prime is 81161086733. The reversal of 81161086722 is 22768016118.

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, 2951428 + ... + 2978799.

It is an arithmetic number, because the mean of its divisors is an integer number (10149585222).

Almost surely, 2^81161086722 is an apocalyptic number.

81161086722 is an abundant number, since it is smaller than the sum of its proper divisors (81232276830).

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

81161086722 is a wasteful number, since it uses less digits than its factorization.

81161086722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5932513.

The product of its (nonzero) digits is 64512, while the sum is 42.

The spelling of 81161086722 in words is "eighty-one billion, one hundred sixty-one million, eighty-six thousand, seven hundred twenty-two".