155521161438 has 32 divisors (see below), whose sum is σ = 329722513920. Its totient is φ = 48734125440.

The previous prime is 155521161431. The next prime is 155521161443. The reversal of 155521161438 is 834161125551.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 155521161438.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155521161431) 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, 799878 + ... + 975113.

It is an arithmetic number, because the mean of its divisors is an integer number (10303828560).

Almost surely, 2^155521161438 is an apocalyptic number.

155521161438 is an abundant number, since it is smaller than the sum of its proper divisors (174201352482).

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

155521161438 is a wasteful number, since it uses less digits than its factorization.

155521161438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1775872.

The product of its digits is 144000, while the sum is 42.

Adding to 155521161438 its reverse (834161125551), we get a palindrome (989682286989).

The spelling of 155521161438 in words is "one hundred fifty-five billion, five hundred twenty-one million, one hundred sixty-one thousand, four hundred thirty-eight".