155220579881 has 4 divisors (see below), whose sum is σ = 160573013700. Its totient is φ = 149868146064.

The previous prime is 155220579847. The next prime is 155220579883. The reversal of 155220579881 is 188975022551.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 188975022551 = 7 ⋅26996431793.

It can be written as a sum of positive squares in 2 ways, for example, as 68141881600 + 87078698281 = 261040^2 + 295091^2 .

It is a cyclic number.

It is not a de Polignac number, because 155220579881 - 2⁶ = 155220579817 is a prime.

It is a super-2 number, since 2×155220579881² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155220579883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2676216866 + ... + 2676216923.

It is an arithmetic number, because the mean of its divisors is an integer number (40143253425).

Almost surely, 2^155220579881 is an apocalyptic number.

It is an amenable number.

155220579881 is a deficient number, since it is larger than the sum of its proper divisors (5352433819).

155220579881 is an equidigital number, since it uses as much as digits as its factorization.

155220579881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5352433818.

The product of its (nonzero) digits is 2016000, while the sum is 53.

The spelling of 155220579881 in words is "one hundred fifty-five billion, two hundred twenty million, five hundred seventy-nine thousand, eight hundred eighty-one".