6640261 has 8 divisors (see below), whose sum is σ = 6955200. Its totient is φ = 6327552.

The previous prime is 6640241. The next prime is 6640289. The reversal of 6640261 is 1620466.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6640261 - 2¹⁵ = 6607493 is a prime.

It is a super-2 number, since 2×6640261² = 88186132296242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10006 + ... + 10648.

It is an arithmetic number, because the mean of its divisors is an integer number (869400).

Almost surely, 2^6640261 is an apocalyptic number.

It is an amenable number.

6640261 is a deficient number, since it is larger than the sum of its proper divisors (314939).

6640261 is a wasteful number, since it uses less digits than its factorization.

6640261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1115.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 6640261 is about 2576.8703886692. The cubic root of 6640261 is about 187.9583901423.

The spelling of 6640261 in words is "six million, six hundred forty thousand, two hundred sixty-one".