646312016653 has 4 divisors (see below), whose sum is σ = 646330087260. Its totient is φ = 646293946048.

The previous prime is 646312016563. The next prime is 646312016663. The reversal of 646312016653 is 356610213646.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 339215386084 + 307096630569 = 582422^2 + 554163^2 .

It is a cyclic number.

It is not a de Polignac number, because 646312016653 - 2³³ = 637722082061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646312016663) 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, 8981548 + ... + 9053221.

It is an arithmetic number, because the mean of its divisors is an integer number (161582521815).

Almost surely, 2^646312016653 is an apocalyptic number.

It is an amenable number.

646312016653 is a deficient number, since it is larger than the sum of its proper divisors (18070607).

646312016653 is a wasteful number, since it uses less digits than its factorization.

646312016653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18070606.

The product of its (nonzero) digits is 466560, while the sum is 43.

The spelling of 646312016653 in words is "six hundred forty-six billion, three hundred twelve million, sixteen thousand, six hundred fifty-three".