666539451 has 24 divisors (see below), whose sum is σ = 1054572480. Its totient is φ = 403796736.

The previous prime is 666539449. The next prime is 666539459. The reversal of 666539451 is 154935666.

It is not a de Polignac number, because 666539451 - 2¹ = 666539449 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 666539397 and 666539406.

It is not an unprimeable number, because it can be changed into a prime (666539459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 70675 + ... + 79548.

It is an arithmetic number, because the mean of its divisors is an integer number (43940520).

Almost surely, 2^666539451 is an apocalyptic number.

666539451 is a deficient number, since it is larger than the sum of its proper divisors (388033029).

666539451 is a wasteful number, since it uses less digits than its factorization.

666539451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150275 (or 150272 counting only the distinct ones).

The product of its digits is 583200, while the sum is 45.

The square root of 666539451 is about 25817.4253363886. The cubic root of 666539451 is about 873.5248946409.

The spelling of 666539451 in words is "six hundred sixty-six million, five hundred thirty-nine thousand, four hundred fifty-one".