81018002 has 8 divisors (see below), whose sum is σ = 130875276. Its totient is φ = 37392912.

The previous prime is 81017969. The next prime is 81018013. The reversal of 81018002 is 20081018.

It is a Cunningham number, because it is equal to 9001²+1.

It can be written as a sum of positive squares in 2 ways, for example, as 81018001 + 1 = 9001^2 + 1^2 .

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, 1558013 + ... + 1558064.

Almost surely, 2^81018002 is an apocalyptic number.

81018002 is a deficient number, since it is larger than the sum of its proper divisors (49857274).

81018002 is a wasteful number, since it uses less digits than its factorization.

81018002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3116092.

The product of its (nonzero) digits is 128, while the sum is 20.

The square root of 81018002 is about 9001.0000555494. Note that the first 4 decimals coincide. The cubic root of 81018002 is about 432.7069222695.

The spelling of 81018002 in words is "eighty-one million, eighteen thousand, two".