133531531638 has 32 divisors (see below), whose sum is σ = 268341964800. Its totient is φ = 44297482176.

The previous prime is 133531531577. The next prime is 133531531703. The reversal of 133531531638 is 836135135331.

It is a self number, because there is not a number n which added to its sum of digits gives 133531531638.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5029683 + ... + 5056161.

It is an arithmetic number, because the mean of its divisors is an integer number (8385686400).

Almost surely, 2^133531531638 is an apocalyptic number.

133531531638 is an abundant number, since it is smaller than the sum of its proper divisors (134810433162).

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

133531531638 is a wasteful number, since it uses less digits than its factorization.

133531531638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30476.

The product of its digits is 291600, while the sum is 42.

Adding to 133531531638 its reverse (836135135331), we get a palindrome (969666666969).

The spelling of 133531531638 in words is "one hundred thirty-three billion, five hundred thirty-one million, five hundred thirty-one thousand, six hundred thirty-eight".