81774004520 has 64 divisors (see below), whose sum is σ = 209800296720. Its totient is φ = 28417388544.

The previous prime is 81774004519. The next prime is 81774004583. The reversal of 81774004520 is 2540047718.

It can be written as a sum of positive squares in 8 ways, for example, as 52961657956 + 28812346564 = 230134^2 + 169742^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4616387 + ... + 4634066.

Almost surely, 2^81774004520 is an apocalyptic number.

It is an amenable number.

81774004520 is an abundant number, since it is smaller than the sum of its proper divisors (128026292200).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81774004520 is a wasteful number, since it uses less digits than its factorization.

81774004520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9250494 (or 9250490 counting only the distinct ones).

The product of its (nonzero) digits is 62720, while the sum is 38.

The spelling of 81774004520 in words is "eighty-one billion, seven hundred seventy-four million, four thousand, five hundred twenty".