81636052 has 6 divisors (see below), whose sum is σ = 142863098. Its totient is φ = 40818024.

The previous prime is 81636047. The next prime is 81636053. The reversal of 81636052 is 25063618.

It can be written as a sum of positive squares in only one way, i.e., 55890576 + 25745476 = 7476^2 + 5074^2 .

It is a super-2 number, since 2×81636052² = 13328889972293408, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81636053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10204503 + ... + 10204510.

Almost surely, 2^81636052 is an apocalyptic number.

It is an amenable number.

81636052 is a deficient number, since it is larger than the sum of its proper divisors (61227046).

81636052 is a wasteful number, since it uses less digits than its factorization.

81636052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20409017 (or 20409015 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 81636052 is about 9035.2671238874. The cubic root of 81636052 is about 433.8044451584.

The spelling of 81636052 in words is "eighty-one million, six hundred thirty-six thousand, fifty-two".