666502642 has 16 divisors (see below), whose sum is σ = 1102919832. Its totient is φ = 300113280.

The previous prime is 666502633. The next prime is 666502649. The reversal of 666502642 is 246205666.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 238054041 + 428448601 = 15429^2 + 20699^2 .

It is not an unprimeable number, because it can be changed into a prime (666502649) 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, 311553 + ... + 313684.

Almost surely, 2^666502642 is an apocalyptic number.

666502642 is a deficient number, since it is larger than the sum of its proper divisors (436417190).

666502642 is a wasteful number, since it uses less digits than its factorization.

666502642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 625293.

The product of its (nonzero) digits is 103680, while the sum is 37.

The square root of 666502642 is about 25816.7124553069. The cubic root of 666502642 is about 873.5088144875.

The spelling of 666502642 in words is "six hundred sixty-six million, five hundred two thousand, six hundred forty-two".