81772786227 has 32 divisors (see below), whose sum is σ = 121405443840. Its totient is φ = 48536309120.

The previous prime is 81772786217. The next prime is 81772786237. The reversal of 81772786227 is 72268727718.

It is an interprime number because it is at equal distance from previous prime (81772786217) and next prime (81772786237).

It is a cyclic number.

It is not a de Polignac number, because 81772786227 - 2⁷ = 81772786099 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81772786217) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 932224 + ... + 1016162.

It is an arithmetic number, because the mean of its divisors is an integer number (3793920120).

Almost surely, 2^81772786227 is an apocalyptic number.

81772786227 is a deficient number, since it is larger than the sum of its proper divisors (39632657613).

81772786227 is a wasteful number, since it uses less digits than its factorization.

81772786227 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84563.

The product of its digits is 7375872, while the sum is 57.

The spelling of 81772786227 in words is "eighty-one billion, seven hundred seventy-two million, seven hundred eighty-six thousand, two hundred twenty-seven".