864416921 has 4 divisors (see below), whose sum is σ = 864478644. Its totient is φ = 864355200.

The previous prime is 864416893. The next prime is 864416923. The reversal of 864416921 is 129614468.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 313998400 + 550418521 = 17720^2 + 23461^2 .

It is a cyclic number.

It is not a de Polignac number, because 864416921 - 2⁶ = 864416857 is a prime.

It is a super-2 number, since 2×864416921² = 1494433226622240482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (864416923) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1361 + ... + 41601.

It is an arithmetic number, because the mean of its divisors is an integer number (216119661).

Almost surely, 2^864416921 is an apocalyptic number.

It is an amenable number.

864416921 is a deficient number, since it is larger than the sum of its proper divisors (61723).

864416921 is a wasteful number, since it uses less digits than its factorization.

864416921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61722.

The product of its digits is 82944, while the sum is 41.

The square root of 864416921 is about 29400.9680282810. The cubic root of 864416921 is about 952.5938058127.

The spelling of 864416921 in words is "eight hundred sixty-four million, four hundred sixteen thousand, nine hundred twenty-one".