81366202 has 4 divisors (see below), whose sum is σ = 122049306. Its totient is φ = 40683100.

The previous prime is 81366193. The next prime is 81366217. The reversal of 81366202 is 20266318.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 20266318 = 2 ⋅10133159.

It can be written as a sum of positive squares in only one way, i.e., 43678881 + 37687321 = 6609^2 + 6139^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20341549 + ... + 20341552.

Almost surely, 2^81366202 is an apocalyptic number.

81366202 is a deficient number, since it is larger than the sum of its proper divisors (40683104).

81366202 is a wasteful number, since it uses less digits than its factorization.

81366202 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40683103.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 81366202 is about 9020.3216128916. The cubic root of 81366202 is about 433.3259337329.

The spelling of 81366202 in words is "eighty-one million, three hundred sixty-six thousand, two hundred two".