816561024 has 64 divisors (see below), whose sum is σ = 2283168000. Its totient is φ = 257859072.

The previous prime is 816561023. The next prime is 816561041. The reversal of 816561024 is 420165618.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-3 number, since 3×816561024³ (a number of 28 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816561023) 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, 48664 + ... + 63255.

It is an arithmetic number, because the mean of its divisors is an integer number (35674500).

Almost surely, 2^816561024 is an apocalyptic number.

It is an amenable number.

816561024 is an abundant number, since it is smaller than the sum of its proper divisors (1466606976).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

816561024 is a wasteful number, since it uses less digits than its factorization.

816561024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111955 (or 111943 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 816561024 is about 28575.5319110599. The cubic root of 816561024 is about 934.6798541714.

The spelling of 816561024 in words is "eight hundred sixteen million, five hundred sixty-one thousand, twenty-four".