816812987 has 8 divisors (see below), whose sum is σ = 828736656. Its totient is φ = 804909312.

The previous prime is 816812981. The next prime is 816812989. The reversal of 816812987 is 789218618.

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

It is a cyclic number.

It is not a de Polignac number, because 816812987 - 2¹² = 816808891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (816812981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90368 + ... + 98994.

It is an arithmetic number, because the mean of its divisors is an integer number (103592082).

Almost surely, 2^816812987 is an apocalyptic number.

816812987 is a deficient number, since it is larger than the sum of its proper divisors (11923669).

816812987 is a wasteful number, since it uses less digits than its factorization.

816812987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9997.

The product of its digits is 387072, while the sum is 50.

The square root of 816812987 is about 28579.9402903505. The cubic root of 816812987 is about 934.7759811047.

The spelling of 816812987 in words is "eight hundred sixteen million, eight hundred twelve thousand, nine hundred eighty-seven".