155389821855 has 32 divisors (see below), whose sum is σ = 261571197888. Its totient is φ = 78668006400.

The previous prime is 155389821823. The next prime is 155389821893. The reversal of 155389821855 is 558128983551.

It is not a de Polignac number, because 155389821855 - 2⁵ = 155389821823 is a prime.

It is a super-2 number, since 2×155389821855² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

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, 3391656 + ... + 3437165.

It is an arithmetic number, because the mean of its divisors is an integer number (8174099934).

Almost surely, 2^155389821855 is an apocalyptic number.

155389821855 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

155389821855 is a deficient number, since it is larger than the sum of its proper divisors (106181376033).

155389821855 is a wasteful number, since it uses less digits than its factorization.

155389821855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6828907.

The product of its digits is 17280000, while the sum is 60.

The spelling of 155389821855 in words is "one hundred fifty-five billion, three hundred eighty-nine million, eight hundred twenty-one thousand, eight hundred fifty-five".