6645166451 has 24 divisors (see below), whose sum is σ = 8358239232. Its totient is φ = 5171482800.

The previous prime is 6645166309. The next prime is 6645166453. The reversal of 6645166451 is 1546615466.

It is not a de Polignac number, because 6645166451 - 2¹⁸ = 6644904307 is a prime.

It is a super-2 number, since 2×6645166451² = 88316474322991870802, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6645166453) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 726416 + ... + 735506.

It is an arithmetic number, because the mean of its divisors is an integer number (348259968).

Almost surely, 2^6645166451 is an apocalyptic number.

6645166451 is a deficient number, since it is larger than the sum of its proper divisors (1713072781).

6645166451 is a wasteful number, since it uses less digits than its factorization.

6645166451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9983 (or 9972 counting only the distinct ones).

The product of its digits is 518400, while the sum is 44.

The square root of 6645166451 is about 81517.8903738314. The cubic root of 6645166451 is about 1880.0466310865.

The spelling of 6645166451 in words is "six billion, six hundred forty-five million, one hundred sixty-six thousand, four hundred fifty-one".