506864921 has 4 divisors (see below), whose sum is σ = 515174244. Its totient is φ = 498555600.

The previous prime is 506864903. The next prime is 506864977. The reversal of 506864921 is 129468605.

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 2 ways, for example, as 252015625 + 254849296 = 15875^2 + 15964^2 .

It is a cyclic number.

It is not a de Polignac number, because 506864921 - 2⁶ = 506864857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (506864621) 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, 4154570 + ... + 4154691.

It is an arithmetic number, because the mean of its divisors is an integer number (128793561).

Almost surely, 2^506864921 is an apocalyptic number.

It is an amenable number.

506864921 is a deficient number, since it is larger than the sum of its proper divisors (8309323).

506864921 is an equidigital number, since it uses as much as digits as its factorization.

506864921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8309322.

The product of its (nonzero) digits is 103680, while the sum is 41.

The square root of 506864921 is about 22513.6607640783. The cubic root of 506864921 is about 797.3164882080.

The spelling of 506864921 in words is "five hundred six million, eight hundred sixty-four thousand, nine hundred twenty-one".