672732521 has 4 divisors (see below), whose sum is σ = 672872772. Its totient is φ = 672592272.

The previous prime is 672732509. The next prime is 672732569. The reversal of 672732521 is 125237276.

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 220106896 + 452625625 = 14836^2 + 21275^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-672732521 is a prime.

It is a super-2 number, since 2×672732521² = 905138089622030882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (672732121) 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, 62666 + ... + 72611.

It is an arithmetic number, because the mean of its divisors is an integer number (168218193).

Almost surely, 2^672732521 is an apocalyptic number.

It is an amenable number.

672732521 is a deficient number, since it is larger than the sum of its proper divisors (140251).

672732521 is a wasteful number, since it uses less digits than its factorization.

672732521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140250.

The product of its digits is 35280, while the sum is 35.

The square root of 672732521 is about 25937.0877509407. The cubic root of 672732521 is about 876.2219752766.

Adding to 672732521 its reverse (125237276), we get a palindrome (797969797).

The spelling of 672732521 in words is "six hundred seventy-two million, seven hundred thirty-two thousand, five hundred twenty-one".