155155603681 has 4 divisors (see below), whose sum is σ = 167090650132. Its totient is φ = 143220557232.

The previous prime is 155155603661. The next prime is 155155603753. The reversal of 155155603681 is 186306551551.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 186306551551 = 16699 ⋅11156749.

It can be written as a sum of positive squares in 2 ways, for example, as 46404053056 + 108751550625 = 215416^2 + 329775^2 .

It is a cyclic number.

It is not a de Polignac number, because 155155603681 - 2¹⁹ = 155155079393 is a prime.

It is a super-2 number, since 2×155155603681² (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 (155155603661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5967523206 + ... + 5967523231.

It is an arithmetic number, because the mean of its divisors is an integer number (41772662533).

Almost surely, 2^155155603681 is an apocalyptic number.

It is an amenable number.

155155603681 is a deficient number, since it is larger than the sum of its proper divisors (11935046451).

155155603681 is a wasteful number, since it uses less digits than its factorization.

155155603681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11935046450.

The product of its (nonzero) digits is 540000, while the sum is 46.

The spelling of 155155603681 in words is "one hundred fifty-five billion, one hundred fifty-five million, six hundred three thousand, six hundred eighty-one".