81774870040 has 64 divisors (see below), whose sum is σ = 187321224960. Its totient is φ = 32120133120.

The previous prime is 81774870029. The next prime is 81774870049. The reversal of 81774870040 is 4007847718.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81774870049) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1453474 + ... + 1508686.

It is an arithmetic number, because the mean of its divisors is an integer number (2926894140).

Almost surely, 2^81774870040 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81774870040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93660612480).

81774870040 is an abundant number, since it is smaller than the sum of its proper divisors (105546354920).

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

81774870040 is a wasteful number, since it uses less digits than its factorization.

81774870040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55892 (or 55888 counting only the distinct ones).

The product of its (nonzero) digits is 351232, while the sum is 46.

It can be divided in two parts, 817748 and 70040, that added together give a palindrome (887788).

The spelling of 81774870040 in words is "eighty-one billion, seven hundred seventy-four million, eight hundred seventy thousand, forty".