671651521 has 16 divisors (see below), whose sum is σ = 721828800. Its totient is φ = 622706688.

The previous prime is 671651507. The next prime is 671651527. The reversal of 671651521 is 125156176.

It is a cyclic number.

It is not a de Polignac number, because 671651521 - 2²³ = 663262913 is a prime.

It is a super-2 number, since 2×671651521² = 902231531323226882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (671651527) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 873025 + ... + 873793.

It is an arithmetic number, because the mean of its divisors is an integer number (45114300).

Almost surely, 2^671651521 is an apocalyptic number.

It is an amenable number.

671651521 is a deficient number, since it is larger than the sum of its proper divisors (50177279).

671651521 is a wasteful number, since it uses less digits than its factorization.

671651521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1488.

The product of its digits is 12600, while the sum is 34.

The square root of 671651521 is about 25916.2404873855. The cubic root of 671651521 is about 875.7523959999.

It can be divided in two parts, 67165 and 1521, that added together give a palindrome (68686).

The spelling of 671651521 in words is "six hundred seventy-one million, six hundred fifty-one thousand, five hundred twenty-one".