1638405064536 has 64 divisors (see below), whose sum is σ = 4122914757600. Its totient is φ = 542549449728.

The previous prime is 1638405064529. The next prime is 1638405064537. The reversal of 1638405064536 is 6354605048361.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1638405064537) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20356020 + ... + 20436348.

Almost surely, 2^{1638405064536} is an apocalyptic number.

It is an amenable number.

1638405064536 is an abundant number, since it is smaller than the sum of its proper divisors (2484509693064).

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

1638405064536 is a wasteful number, since it uses less digits than its factorization.

1638405064536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85908 (or 85904 counting only the distinct ones).

The product of its (nonzero) digits is 6220800, while the sum is 51.

The spelling of 1638405064536 in words is "one trillion, six hundred thirty-eight billion, four hundred five million, sixty-four thousand, five hundred thirty-six".