642443707436540 has 24 divisors (see below), whose sum is σ = 1349837029704240. Its totient is φ = 256843150767488.

The previous prime is 642443707436449. The next prime is 642443707436581. The reversal of 642443707436540 is 45634707344246.

It is a self number, because there is not a number n which added to its sum of digits gives 642443707436540.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8395723730 + ... + 8395800249.

It is an arithmetic number, because the mean of its divisors is an integer number (56243209571010).

Almost surely, 2^{642443707436540} is an apocalyptic number.

It is an amenable number.

642443707436540 is an abundant number, since it is smaller than the sum of its proper divisors (707393322267700).

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

642443707436540 is a wasteful number, since it uses less digits than its factorization.

642443707436540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16791525901 (or 16791525899 counting only the distinct ones).

The product of its (nonzero) digits is 162570240, while the sum is 59.

The spelling of 642443707436540 in words is "six hundred forty-two trillion, four hundred forty-three billion, seven hundred seven million, four hundred thirty-six thousand, five hundred forty".