81542248719 has 16 divisors (see below), whose sum is σ = 114618979200. Its totient is φ = 51422194656.

The previous prime is 81542248717. The next prime is 81542248721. The reversal of 81542248719 is 91784224518.

It is an interprime number because it is at equal distance from previous prime (81542248717) and next prime (81542248721).

It is not a de Polignac number, because 81542248719 - 2¹ = 81542248717 is a prime.

It is a super-2 number, since 2×81542248719² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81542248717) 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, 1047844 + ... + 1122969.

It is an arithmetic number, because the mean of its divisors is an integer number (7163686200).

Almost surely, 2^81542248719 is an apocalyptic number.

81542248719 is a deficient number, since it is larger than the sum of its proper divisors (33076730481).

81542248719 is a wasteful number, since it uses less digits than its factorization.

81542248719 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2171494.

The product of its digits is 1290240, while the sum is 51.

The spelling of 81542248719 in words is "eighty-one billion, five hundred forty-two million, two hundred forty-eight thousand, seven hundred nineteen".