81537746120602 has 4 divisors (see below), whose sum is σ = 122306619180906. Its totient is φ = 40768873060300.

The previous prime is 81537746120591. The next prime is 81537746120669. The reversal of 81537746120602 is 20602164773518.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 79827774060321 + 1709972060281 = 8934639^2 + 1307659^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81537746120602.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20384436530149 + ... + 20384436530152.

Almost surely, 2^{81537746120602} is an apocalyptic number.

81537746120602 is a deficient number, since it is larger than the sum of its proper divisors (40768873060304).

81537746120602 is a wasteful number, since it uses less digits than its factorization.

81537746120602 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40768873060303.

The product of its (nonzero) digits is 3386880, while the sum is 52.

The spelling of 81537746120602 in words is "eighty-one trillion, five hundred thirty-seven billion, seven hundred forty-six million, one hundred twenty thousand, six hundred two".