816403887 has 32 divisors (see below), whose sum is σ = 1306645760. Its totient is φ = 500813280.

The previous prime is 816403873. The next prime is 816403897. The reversal of 816403887 is 788304618.

It is not a de Polignac number, because 816403887 - 2¹⁹ = 815879599 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816403897) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 112668 + ... + 119694.

It is an arithmetic number, because the mean of its divisors is an integer number (40832680).

Almost surely, 2^816403887 is an apocalyptic number.

816403887 is a deficient number, since it is larger than the sum of its proper divisors (490241873).

816403887 is a wasteful number, since it uses less digits than its factorization.

816403887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7380 (or 7374 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 45.

The square root of 816403887 is about 28572.7822761452. The cubic root of 816403887 is about 934.6198944924.

The spelling of 816403887 in words is "eight hundred sixteen million, four hundred three thousand, eight hundred eighty-seven".