155511481 has 4 divisors (see below), whose sum is σ = 159714532. Its totient is φ = 151308432.

The previous prime is 155511463. The next prime is 155511497. The reversal of 155511481 is 184115551.

155511481 = 1413² + 1414² + ... + 1486².

155511481 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 an emirpimes, since its reverse is a distinct semiprime: 184115551 = 43 ⋅4281757.

It can be written as a sum of positive squares in 2 ways, for example, as 120890025 + 34621456 = 10995^2 + 5884^2 .

It is a cyclic number.

It is not a de Polignac number, because 155511481 - 2⁷ = 155511353 is a prime.

It is a super-2 number, since 2×155511481² = 48367641445626722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155511451) 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, 2101470 + ... + 2101543.

It is an arithmetic number, because the mean of its divisors is an integer number (39928633).

Almost surely, 2^155511481 is an apocalyptic number.

It is an amenable number.

155511481 is a deficient number, since it is larger than the sum of its proper divisors (4203051).

155511481 is an equidigital number, since it uses as much as digits as its factorization.

155511481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4203050.

The product of its digits is 4000, while the sum is 31.

The square root of 155511481 is about 12470.4242510029. The cubic root of 155511481 is about 537.7587501979.

The spelling of 155511481 in words is "one hundred fifty-five million, five hundred eleven thousand, four hundred eighty-one".