81634775524 has 27 divisors (see below), whose sum is σ = 143619873033. Its totient is φ = 40601670672.

The previous prime is 81634775507. The next prime is 81634775543. The reversal of 81634775524 is 42557743618.

The square root of 81634775524 is 285718.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 44373422500 + 37261353024 = 210650^2 + 193032^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 213145437 + ... + 213145819.

Almost surely, 2^81634775524 is an apocalyptic number.

81634775524 is the 285718-th square number.

It is an amenable number.

81634775524 is a deficient number, since it is larger than the sum of its proper divisors (61985097509).

81634775524 is an frugal number, since it uses more digits than its factorization.

81634775524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1516 (or 758 counting only the distinct ones).

The product of its digits is 5644800, while the sum is 52.

The spelling of 81634775524 in words is "eighty-one billion, six hundred thirty-four million, seven hundred seventy-five thousand, five hundred twenty-four".