643221542545 has 32 divisors (see below), whose sum is σ = 791650713600. Its totient is φ = 501485199360.

The previous prime is 643221542519. The next prime is 643221542573. The reversal of 643221542545 is 545245122346.

It is not a de Polignac number, because 643221542545 - 2¹³ = 643221534353 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 57687631 + ... + 57698779.

It is an arithmetic number, because the mean of its divisors is an integer number (24739084800).

Almost surely, 2^643221542545 is an apocalyptic number.

It is an amenable number.

643221542545 is a deficient number, since it is larger than the sum of its proper divisors (148429171055).

643221542545 is a wasteful number, since it uses less digits than its factorization.

643221542545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12225.

The product of its digits is 1152000, while the sum is 43.

The spelling of 643221542545 in words is "six hundred forty-three billion, two hundred twenty-one million, five hundred forty-two thousand, five hundred forty-five".