645142142123520 has 640 divisors, whose sum is σ = 2148842265292800. Its totient is φ = 164919575052288.

The previous prime is 645142142123513. The next prime is 645142142123533. The reversal of 645142142123520 is 25321241241546.

It is a tau number, because it is divible by the number of its divisors (640).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 18823609104 + ... + 18823643376.

It is an arithmetic number, because the mean of its divisors is an integer number (3357566039520).

Almost surely, 2^{645142142123520} is an apocalyptic number.

645142142123520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645142142123520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1074421132646400).

645142142123520 is an abundant number, since it is smaller than the sum of its proper divisors (1503700123169280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645142142123520 is a wasteful number, since it uses less digits than its factorization.

645142142123520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34930 (or 34914 counting only the distinct ones).

The product of its (nonzero) digits is 460800, while the sum is 42.

The spelling of 645142142123520 in words is "six hundred forty-five trillion, one hundred forty-two billion, one hundred forty-two million, one hundred twenty-three thousand, five hundred twenty".