646561531015 has 8 divisors (see below), whose sum is σ = 775958585328. Its totient is φ = 517192726080.

The previous prime is 646561531013. The next prime is 646561531051. The reversal of 646561531015 is 510135165646.

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

It is not a de Polignac number, because 646561531015 - 2¹ = 646561531013 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 (646561531013) 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, 7011957 + ... + 7103566.

It is an arithmetic number, because the mean of its divisors is an integer number (96994823166).

Almost surely, 2^646561531015 is an apocalyptic number.

646561531015 is a deficient number, since it is larger than the sum of its proper divisors (129397054313).

646561531015 is a wasteful number, since it uses less digits than its factorization.

646561531015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14124689.

The product of its (nonzero) digits is 324000, while the sum is 43.

The spelling of 646561531015 in words is "six hundred forty-six billion, five hundred sixty-one million, five hundred thirty-one thousand, fifteen".