155516212081 has 4 divisors (see below), whose sum is σ = 156740749312. Its totient is φ = 154291674852.

The previous prime is 155516212073. The next prime is 155516212139. The reversal of 155516212081 is 180212615551.

155516212081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 180212615551 = 131 ⋅1375668821.

It is a cyclic number.

It is not a de Polignac number, because 155516212081 - 2³ = 155516212073 is a prime.

It is a super-2 number, since 2×155516212081² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 155516212081.

It is not an unprimeable number, because it can be changed into a prime (155516212001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 612268425 + ... + 612268678.

It is an arithmetic number, because the mean of its divisors is an integer number (39185187328).

Almost surely, 2^155516212081 is an apocalyptic number.

It is an amenable number.

155516212081 is a deficient number, since it is larger than the sum of its proper divisors (1224537231).

155516212081 is a wasteful number, since it uses less digits than its factorization.

155516212081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1224537230.

The product of its (nonzero) digits is 24000, while the sum is 37.

The spelling of 155516212081 in words is "one hundred fifty-five billion, five hundred sixteen million, two hundred twelve thousand, eighty-one".