81542982968 has 8 divisors (see below), whose sum is σ = 152893093080. Its totient is φ = 40771491480.

The previous prime is 81542982953. The next prime is 81542982979. The reversal of 81542982968 is 86928924518.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 81542982968.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5096436428 + ... + 5096436443.

It is an arithmetic number, because the mean of its divisors is an integer number (19111636635).

Almost surely, 2^81542982968 is an apocalyptic number.

It is an amenable number.

81542982968 is a deficient number, since it is larger than the sum of its proper divisors (71350110112).

81542982968 is a wasteful number, since it uses less digits than its factorization.

81542982968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10192872877 (or 10192872873 counting only the distinct ones).

The product of its digits is 19906560, while the sum is 62.

The spelling of 81542982968 in words is "eighty-one billion, five hundred forty-two million, nine hundred eighty-two thousand, nine hundred sixty-eight".