91745986816 has 81 divisors (see below), whose sum is σ = 201412632169. Its totient is φ = 41678489600.

The previous prime is 91745986799. The next prime is 91745986823. The reversal of 91745986816 is 61868954719.

The square root of 91745986816 is 302896.

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., 67758172416 + 23987814400 = 260304^2 + 154880^2 .

It is a Harshad number since it is a multiple of its sum of digits (64).

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, 53308836 + ... + 53310556.

Almost surely, 2^91745986816 is an apocalyptic number.

91745986816 is the 302896-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91745986816

91745986816 is an abundant number, since it is smaller than the sum of its proper divisors (109666645353).

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

91745986816 is an frugal number, since it uses more digits than its factorization.

91745986816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3480 (or 1734 counting only the distinct ones).

The product of its digits is 26127360, while the sum is 64.

Multiplying 91745986816 by its sum of digits (64), we get a square (5871743156224 = 2423168²).

91745986816 divided by its sum of digits (64) gives a square (1433531044 = 37862²).

The spelling of 91745986816 in words is "ninety-one billion, seven hundred forty-five million, nine hundred eighty-six thousand, eight hundred sixteen".