81626435252 has 12 divisors (see below), whose sum is σ = 143888936100. Its totient is φ = 40515310656.

The previous prime is 81626435167. The next prime is 81626435257. The reversal of 81626435252 is 25253462618.

It can be written as a sum of positive squares in 2 ways, for example, as 55240981156 + 26385454096 = 235034^2 + 162436^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81626435257) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 74476127 + ... + 74477222.

It is an arithmetic number, because the mean of its divisors is an integer number (11990744675).

Almost surely, 2^81626435252 is an apocalyptic number.

It is an amenable number.

81626435252 is a deficient number, since it is larger than the sum of its proper divisors (62262500848).

81626435252 is a wasteful number, since it uses less digits than its factorization.

81626435252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148953490 (or 148953488 counting only the distinct ones).

The product of its digits is 691200, while the sum is 44.

The spelling of 81626435252 in words is "eighty-one billion, six hundred twenty-six million, four hundred thirty-five thousand, two hundred fifty-two".