81336251051 has 16 divisors (see below), whose sum is σ = 90908034048. Its totient is φ = 72137457600.

The previous prime is 81336251027. The next prime is 81336251057. The reversal of 81336251051 is 15015263318.

It is a cyclic number.

It is not a de Polignac number, because 81336251051 - 2²² = 81332056747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81336251057) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 89495 + ... + 413136.

It is an arithmetic number, because the mean of its divisors is an integer number (5681752128).

Almost surely, 2^81336251051 is an apocalyptic number.

81336251051 is a deficient number, since it is larger than the sum of its proper divisors (9571782997).

81336251051 is a wasteful number, since it uses less digits than its factorization.

81336251051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 503002.

The product of its (nonzero) digits is 21600, while the sum is 35.

The spelling of 81336251051 in words is "eighty-one billion, three hundred thirty-six million, two hundred fifty-one thousand, fifty-one".