81015225953 has 2 divisors, whose sum is σ = 81015225954. Its totient is φ = 81015225952.

The previous prime is 81015225943. The next prime is 81015226003. The reversal of 81015225953 is 35952251018.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80660544064 + 354681889 = 284008^2 + 18833^2 .

It is a cyclic number.

It is not a de Polignac number, because 81015225953 - 2²² = 81011031649 is a prime.

It is a super-5 number, since 5×81015225953⁵ (a number of 56 digits) contains 55555 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81015225953.

It is not a weakly prime, because it can be changed into another prime (81015225913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40507612976 + 40507612977.

It is an arithmetic number, because the mean of its divisors is an integer number (40507612977).

Almost surely, 2^81015225953 is an apocalyptic number.

It is an amenable number.

81015225953 is a deficient number, since it is larger than the sum of its proper divisors (1).

81015225953 is an equidigital number, since it uses as much as digits as its factorization.

81015225953 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108000, while the sum is 41.

The spelling of 81015225953 in words is "eighty-one billion, fifteen million, two hundred twenty-five thousand, nine hundred fifty-three".