645143123536 has 10 divisors (see below), whose sum is σ = 1249964801882. Its totient is φ = 322571561760.

The previous prime is 645143123533. The next prime is 645143123543. The reversal of 645143123536 is 635321341546.

It can be written as a sum of positive squares in only one way, i.e., 625048360000 + 20094763536 = 790600^2 + 141756^2 .

It is a junction number, because it is equal to n+sod(n) for n = 645143123492 and 645143123501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645143123533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20160722595 + ... + 20160722626.

Almost surely, 2^645143123536 is an apocalyptic number.

It is an amenable number.

645143123536 is a deficient number, since it is larger than the sum of its proper divisors (604821678346).

645143123536 is a wasteful number, since it uses less digits than its factorization.

645143123536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40321445229 (or 40321445223 counting only the distinct ones).

The product of its digits is 777600, while the sum is 43.

The spelling of 645143123536 in words is "six hundred forty-five billion, one hundred forty-three million, one hundred twenty-three thousand, five hundred thirty-six".