645606556023 has 32 divisors (see below), whose sum is σ = 1011999647232. Its totient is φ = 360928540800.

The previous prime is 645606555929. The next prime is 645606556079. The reversal of 645606556023 is 320655606546.

It is not a de Polignac number, because 645606556023 - 2⁸ = 645606555767 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645606556093) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 100753 + ... + 1140773.

It is an arithmetic number, because the mean of its divisors is an integer number (31624988976).

Almost surely, 2^645606556023 is an apocalyptic number.

645606556023 is a deficient number, since it is larger than the sum of its proper divisors (366393091209).

645606556023 is a wasteful number, since it uses less digits than its factorization.

645606556023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1041495.

The product of its (nonzero) digits is 3888000, while the sum is 48.

The spelling of 645606556023 in words is "six hundred forty-five billion, six hundred six million, five hundred fifty-six thousand, twenty-three".