81542248161 has 32 divisors (see below), whose sum is σ = 128646838656. Its totient is φ = 45378048000.

The previous prime is 81542248153. The next prime is 81542248163. The reversal of 81542248161 is 16184224518.

It is not a de Polignac number, because 81542248161 - 2³ = 81542248153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81542248163) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1749580 + ... + 1795581.

It is an arithmetic number, because the mean of its divisors is an integer number (4020213708).

Almost surely, 2^81542248161 is an apocalyptic number.

It is an amenable number.

81542248161 is a deficient number, since it is larger than the sum of its proper divisors (47104590495).

81542248161 is a wasteful number, since it uses less digits than its factorization.

81542248161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3545233.

The product of its digits is 122880, while the sum is 42.

The spelling of 81542248161 in words is "eighty-one billion, five hundred forty-two million, two hundred forty-eight thousand, one hundred sixty-one".