646426066402 has 8 divisors (see below), whose sum is σ = 987934177116. Its totient is φ = 317114674032.

The previous prime is 646426066399. The next prime is 646426066409. The reversal of 646426066402 is 204660624646.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 644923031041 + 1503035361 = 803071^2 + 38769^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (646426066409) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3049179453 + ... + 3049179664.

Almost surely, 2^646426066402 is an apocalyptic number.

646426066402 is a deficient number, since it is larger than the sum of its proper divisors (341508110714).

646426066402 is a wasteful number, since it uses less digits than its factorization.

646426066402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6098359172.

The product of its (nonzero) digits is 1990656, while the sum is 46.

The spelling of 646426066402 in words is "six hundred forty-six billion, four hundred twenty-six million, sixty-six thousand, four hundred two".