81326874778 has 16 divisors (see below), whose sum is σ = 122944456800. Its totient is φ = 40345505200.

The previous prime is 81326874737. The next prime is 81326874779. The reversal of 81326874778 is 87747862318.

It is a super-2 number, since 2×81326874778² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81326874779) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1541073 + ... + 1592971.

It is an arithmetic number, because the mean of its divisors is an integer number (7684028550).

Almost surely, 2^81326874778 is an apocalyptic number.

81326874778 is a deficient number, since it is larger than the sum of its proper divisors (41617582022).

81326874778 is a wasteful number, since it uses less digits than its factorization.

81326874778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58013.

The product of its digits is 25288704, while the sum is 61.

The spelling of 81326874778 in words is "eighty-one billion, three hundred twenty-six million, eight hundred seventy-four thousand, seven hundred seventy-eight".