645116551651 has 16 divisors (see below), whose sum is σ = 758048659200. Its totient is φ = 541249765920.

The previous prime is 645116551609. The next prime is 645116551663. The reversal of 645116551651 is 156155611546.

It is a cyclic number.

It is not a de Polignac number, because 645116551651 - 2¹⁷ = 645116420579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645116551601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 286786 + ... + 1171528.

It is an arithmetic number, because the mean of its divisors is an integer number (47378041200).

Almost surely, 2^645116551651 is an apocalyptic number.

645116551651 is a deficient number, since it is larger than the sum of its proper divisors (112932107549).

645116551651 is a wasteful number, since it uses less digits than its factorization.

645116551651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 889866.

The product of its digits is 540000, while the sum is 46.

The spelling of 645116551651 in words is "six hundred forty-five billion, one hundred sixteen million, five hundred fifty-one thousand, six hundred fifty-one".