81510712051 has 2 divisors, whose sum is σ = 81510712052. Its totient is φ = 81510712050.

The previous prime is 81510712009. The next prime is 81510712057. The reversal of 81510712051 is 15021701518.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81510712051 - 2¹¹ = 81510710003 is a prime.

It is a super-2 number, since 2×81510712051² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81510712057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40755356025 + 40755356026.

It is an arithmetic number, because the mean of its divisors is an integer number (40755356026).

Almost surely, 2^81510712051 is an apocalyptic number.

81510712051 is a deficient number, since it is larger than the sum of its proper divisors (1).

81510712051 is an equidigital number, since it uses as much as digits as its factorization.

81510712051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2800, while the sum is 31.

The spelling of 81510712051 in words is "eighty-one billion, five hundred ten million, seven hundred twelve thousand, fifty-one".