645606556051 has 8 divisors (see below), whose sum is σ = 650555136000. Its totient is φ = 640658283720.

The previous prime is 645606555929. The next prime is 645606556079. The reversal of 645606556051 is 150655606546.

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 645606556051 - 2¹⁵ = 645606523283 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645606555986 and 645606556004.

It is not an unprimeable number, because it can be changed into a prime (645606553051) 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, 5919430 + ... + 6027508.

It is an arithmetic number, because the mean of its divisors is an integer number (81319392000).

Almost surely, 2^645606556051 is an apocalyptic number.

645606556051 is a deficient number, since it is larger than the sum of its proper divisors (4948579949).

645606556051 is a wasteful number, since it uses less digits than its factorization.

645606556051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153809.

The product of its (nonzero) digits is 3240000, while the sum is 49.

The spelling of 645606556051 in words is "six hundred forty-five billion, six hundred six million, five hundred fifty-six thousand, fifty-one".