6721440525 has 36 divisors (see below), whose sum is σ = 12060234420. Its totient is φ = 3578400000.

The previous prime is 6721440457. The next prime is 6721440527. The reversal of 6721440525 is 5250441276.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 1186526916 + 5534913609 = 34446^2 + 74397^2 .

It is not a de Polignac number, because 6721440525 - 2⁸ = 6721440269 is a prime.

It is a super-2 number, since 2×6721440525² = 90355525462224551250, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 6721440525.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6721440527) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 101775 + ... + 154275.

Almost surely, 2^6721440525 is an apocalyptic number.

It is an amenable number.

6721440525 is a deficient number, since it is larger than the sum of its proper divisors (5338793895).

6721440525 is a wasteful number, since it uses less digits than its factorization.

6721440525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53086 (or 53078 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 36.

The square root of 6721440525 is about 81984.3919596895. The cubic root of 6721440525 is about 1887.2124228920.

The spelling of 6721440525 in words is "six billion, seven hundred twenty-one million, four hundred forty thousand, five hundred twenty-five".