145655581 has 4 divisors (see below), whose sum is σ = 145763964. Its totient is φ = 145547200.

The previous prime is 145655579. The next prime is 145655591. The reversal of 145655581 is 185556541.

145655581 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.

It can be written as a sum of positive squares in 2 ways, for example, as 12460900 + 133194681 = 3530^2 + 11541^2 .

It is a cyclic number.

It is not a de Polignac number, because 145655581 - 2¹ = 145655579 is a prime.

It is a super-2 number, since 2×145655581² = 42431096552895122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145655561) 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, 52150 + ... + 54871.

It is an arithmetic number, because the mean of its divisors is an integer number (36440991).

Almost surely, 2^145655581 is an apocalyptic number.

It is an amenable number.

145655581 is a deficient number, since it is larger than the sum of its proper divisors (108383).

145655581 is a wasteful number, since it uses less digits than its factorization.

145655581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108382.

The product of its digits is 120000, while the sum is 40.

The square root of 145655581 is about 12068.7853987052. The cubic root of 145655581 is about 526.1493561612.

The spelling of 145655581 in words is "one hundred forty-five million, six hundred fifty-five thousand, five hundred eighty-one".