155513315551 has 4 divisors (see below), whose sum is σ = 169650889704. Its totient is φ = 141375741400.

The previous prime is 155513315549. The next prime is 155513315579.

155513315551 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 155513315551 - 2¹ = 155513315549 is a prime.

It is a super-3 number, since 3×155513315551³ (a number of 35 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155513315501) 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, 7068787060 + ... + 7068787081.

It is an arithmetic number, because the mean of its divisors is an integer number (42412722426).

Almost surely, 2^155513315551 is an apocalyptic number.

155513315551 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

155513315551 is a deficient number, since it is larger than the sum of its proper divisors (14137574153).

155513315551 is a wasteful number, since it uses less digits than its factorization.

155513315551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14137574152.

The product of its digits is 140625, while the sum is 40.

The spelling of 155513315551 in words is "one hundred fifty-five billion, five hundred thirteen million, three hundred fifteen thousand, five hundred fifty-one".