81090602 has 8 divisors (see below), whose sum is σ = 121699236. Its totient is φ = 40524192.

The previous prime is 81090593. The next prime is 81090623. The reversal of 81090602 is 20609018.

It can be written as a sum of positive squares in 2 ways, for example, as 71048041 + 10042561 = 8429^2 + 3169^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5213 + ... + 13760.

Almost surely, 2^81090602 is an apocalyptic number.

81090602 is a deficient number, since it is larger than the sum of its proper divisors (40608634).

81090602 is a wasteful number, since it uses less digits than its factorization.

81090602 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21112.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 81090602 is about 9005.0320376998. The cubic root of 81090602 is about 432.8361328275.

The spelling of 81090602 in words is "eighty-one million, ninety thousand, six hundred two".