81500772455 has 4 divisors (see below), whose sum is σ = 97800926952. Its totient is φ = 65200617960.

The previous prime is 81500772449. The next prime is 81500772473. The reversal of 81500772455 is 55427700518.

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

It is not a de Polignac number, because 81500772455 - 2¹² = 81500768359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8150077241 + ... + 8150077250.

It is an arithmetic number, because the mean of its divisors is an integer number (24450231738).

Almost surely, 2^81500772455 is an apocalyptic number.

81500772455 is a deficient number, since it is larger than the sum of its proper divisors (16300154497).

81500772455 is a wasteful number, since it uses less digits than its factorization.

81500772455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16300154496.

The product of its (nonzero) digits is 392000, while the sum is 44.

The spelling of 81500772455 in words is "eighty-one billion, five hundred million, seven hundred seventy-two thousand, four hundred fifty-five".