81161615470 has 32 divisors (see below), whose sum is σ = 164169052992. Its totient is φ = 28664435712.

The previous prime is 81161615419. The next prime is 81161615471. The reversal of 81161615470 is 7451616118.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81161615471) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13569187 + ... + 13575166.

It is an arithmetic number, because the mean of its divisors is an integer number (5130282906).

Almost surely, 2^81161615470 is an apocalyptic number.

81161615470 is an abundant number, since it is smaller than the sum of its proper divisors (83007437522).

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

81161615470 is a wasteful number, since it uses less digits than its factorization.

81161615470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27144396.

The product of its (nonzero) digits is 40320, while the sum is 40.

The spelling of 81161615470 in words is "eighty-one billion, one hundred sixty-one million, six hundred fifteen thousand, four hundred seventy".