81432904354 has 4 divisors (see below), whose sum is σ = 122149356534. Its totient is φ = 40716452176.

The previous prime is 81432904351. The next prime is 81432904391. The reversal of 81432904354 is 45340923418.

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., 76245015625 + 5187888729 = 276125^2 + 72027^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81432904354.

It is not an unprimeable number, because it can be changed into a prime (81432904351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20358226087 + ... + 20358226090.

Almost surely, 2^81432904354 is an apocalyptic number.

81432904354 is a deficient number, since it is larger than the sum of its proper divisors (40716452180).

81432904354 is a wasteful number, since it uses less digits than its factorization.

81432904354 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40716452179.

The product of its (nonzero) digits is 414720, while the sum is 43.

The spelling of 81432904354 in words is "eighty-one billion, four hundred thirty-two million, nine hundred four thousand, three hundred fifty-four".