521421672 has 16 divisors (see below), whose sum is σ = 1303554240. Its totient is φ = 173807216.

The previous prime is 521421623. The next prime is 521421673. The reversal of 521421672 is 276124125.

It is not an unprimeable number, because it can be changed into a prime (521421673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10862928 + ... + 10862975.

It is an arithmetic number, because the mean of its divisors is an integer number (81472140).

Almost surely, 2^521421672 is an apocalyptic number.

It is an amenable number.

521421672 is an abundant number, since it is smaller than the sum of its proper divisors (782132568).

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

521421672 is a wasteful number, since it uses less digits than its factorization.

521421672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21725912 (or 21725908 counting only the distinct ones).

The product of its digits is 6720, while the sum is 30.

The square root of 521421672 is about 22834.6594456760. The cubic root of 521421672 is about 804.8773250302.

Adding to 521421672 its reverse (276124125), we get a palindrome (797545797).

The spelling of 521421672 in words is "five hundred twenty-one million, four hundred twenty-one thousand, six hundred seventy-two".