6465607281 has 45 divisors (see below), whose sum is σ = 10915051641. Its totient is φ = 3687878376.

The previous prime is 6465607271. The next prime is 6465607283. The reversal of 6465607281 is 1827065646.

The square root of 6465607281 is 80409.

It is a perfect power (a square), and thus also a powerful number.

6465607281 is a `hidden beast` number, since 6 + 4 + 6 + 560 + 7 + 2 + 81 = 666.

It is not a de Polignac number, because 6465607281 - 2⁵ = 6465607249 is a prime.

It is a super-2 number, since 2×6465607281² = 83608155024240425922, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6465607283) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 11819850 + ... + 11820396.

Almost surely, 2^6465607281 is an apocalyptic number.

6465607281 is the 80409-th square number.

6465607281 is the 40205-th centered octagonal number.

It is an amenable number.

6465607281 is a deficient number, since it is larger than the sum of its proper divisors (4449444360).

6465607281 is an frugal number, since it uses more digits than its factorization.

6465607281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1128 (or 557 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The cubic root of 6465607281 is about 1862.9581864258.

The spelling of 6465607281 in words is "six billion, four hundred sixty-five million, six hundred seven thousand, two hundred eighty-one".