81655202 has 4 divisors (see below), whose sum is σ = 122482806. Its totient is φ = 40827600.

The previous prime is 81655201. The next prime is 81655247. The reversal of 81655202 is 20255618.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 20255618 = 2 ⋅10127809.

It can be written as a sum of positive squares in only one way, i.e., 45306361 + 36348841 = 6731^2 + 6029^2 .

It is a super-3 number, since 3×81655202³ (a number of 25 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (81655201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20413799 + ... + 20413802.

Almost surely, 2^81655202 is an apocalyptic number.

81655202 is a deficient number, since it is larger than the sum of its proper divisors (40827604).

81655202 is a wasteful number, since it uses less digits than its factorization.

81655202 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40827603.

The product of its (nonzero) digits is 4800, while the sum is 29.

The square root of 81655202 is about 9036.3267979860. The cubic root of 81655202 is about 433.8383627942.

The spelling of 81655202 in words is "eighty-one million, six hundred fifty-five thousand, two hundred two".