81049400144 has 30 divisors (see below), whose sum is σ = 157289294634. Its totient is φ = 40458721600.

The previous prime is 81049400143. The next prime is 81049400161. The reversal of 81049400144 is 44100494018.

It can be written as a sum of positive squares in only one way, i.e., 81042702400 + 6697744 = 284680^2 + 2588^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81049400143) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6691694 + ... + 6703794.

Almost surely, 2^81049400144 is an apocalyptic number.

It is an amenable number.

81049400144 is a deficient number, since it is larger than the sum of its proper divisors (76239894490).

81049400144 is an equidigital number, since it uses as much as digits as its factorization.

81049400144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13403 (or 12750 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 35.

The spelling of 81049400144 in words is "eighty-one billion, forty-nine million, four hundred thousand, one hundred forty-four".