81776800954 has 4 divisors (see below), whose sum is σ = 122665201434. Its totient is φ = 40888400476.

The previous prime is 81776800921. The next prime is 81776800957. The reversal of 81776800954 is 45900867718.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 71286330025 + 10490470929 = 266995^2 + 102423^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81776800895 and 81776800904.

It is not an unprimeable number, because it can be changed into a prime (81776800957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20444200237 + ... + 20444200240.

Almost surely, 2^81776800954 is an apocalyptic number.

81776800954 is a deficient number, since it is larger than the sum of its proper divisors (40888400480).

81776800954 is a wasteful number, since it uses less digits than its factorization.

81776800954 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40888400479.

The product of its (nonzero) digits is 3386880, while the sum is 55.

The spelling of 81776800954 in words is "eighty-one billion, seven hundred seventy-six million, eight hundred thousand, nine hundred fifty-four".