666402445 has 8 divisors (see below), whose sum is σ = 802571544. Its totient is φ = 531196224.

The previous prime is 666402419. The next prime is 666402461. The reversal of 666402445 is 544204666.

It can be written as a sum of positive squares in 4 ways, for example, as 4318084 + 662084361 = 2078^2 + 25731^2 .

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 666402445 - 2²⁹ = 129531533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 239194 + ... + 241963.

It is an arithmetic number, because the mean of its divisors is an integer number (100321443).

Almost surely, 2^666402445 is an apocalyptic number.

It is an amenable number.

666402445 is a deficient number, since it is larger than the sum of its proper divisors (136169099).

666402445 is a wasteful number, since it uses less digits than its factorization.

666402445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481439.

The product of its (nonzero) digits is 138240, while the sum is 37.

The square root of 666402445 is about 25814.7718370703. The cubic root of 666402445 is about 873.4650400429.

The spelling of 666402445 in words is "six hundred sixty-six million, four hundred two thousand, four hundred forty-five".