645839422971 has 16 divisors (see below), whose sum is σ = 873344021760. Its totient is φ = 424448558240.

The previous prime is 645839422967. The next prime is 645839422973. The reversal of 645839422971 is 179224938546.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 645839422971 - 2² = 645839422967 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645839422973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1823185 + ... + 2148413.

It is an arithmetic number, because the mean of its divisors is an integer number (54584001360).

Almost surely, 2^645839422971 is an apocalyptic number.

645839422971 is a deficient number, since it is larger than the sum of its proper divisors (227504598789).

645839422971 is a wasteful number, since it uses less digits than its factorization.

645839422971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334626.

The product of its digits is 26127360, while the sum is 60.

The spelling of 645839422971 in words is "six hundred forty-five billion, eight hundred thirty-nine million, four hundred twenty-two thousand, nine hundred seventy-one".