815871002 has 4 divisors (see below), whose sum is σ = 1223806506. Its totient is φ = 407935500.

The previous prime is 815870981. The next prime is 815871059. The reversal of 815871002 is 200178518.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 810483961 + 5387041 = 28469^2 + 2321^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 815871002.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 203967749 + ... + 203967752.

Almost surely, 2^815871002 is an apocalyptic number.

815871002 is a deficient number, since it is larger than the sum of its proper divisors (407935504).

815871002 is a wasteful number, since it uses less digits than its factorization.

815871002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407935503.

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 815871002 is about 28563.4557082997. The cubic root of 815871002 is about 934.4165011592.

The spelling of 815871002 in words is "eight hundred fifteen million, eight hundred seventy-one thousand, two".