145189891 has 24 divisors (see below), whose sum is σ = 186214896. Its totient is φ = 111928320.

The previous prime is 145189867. The next prime is 145189901. The reversal of 145189891 is 198981541.

It is not a de Polignac number, because 145189891 - 2¹¹ = 145187843 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145189831) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50895 + ... + 53671.

It is an arithmetic number, because the mean of its divisors is an integer number (7758954).

Almost surely, 2^145189891 is an apocalyptic number.

145189891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

145189891 is a deficient number, since it is larger than the sum of its proper divisors (41025005).

145189891 is a wasteful number, since it uses less digits than its factorization.

145189891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2899 (or 2892 counting only the distinct ones).

The product of its digits is 103680, while the sum is 46.

The square root of 145189891 is about 12049.4767936205. The cubic root of 145189891 is about 525.5880226249.

It can be divided in two parts, 145 and 189891, that added together give a triangular number (190036 = T₆₁₆).

The spelling of 145189891 in words is "one hundred forty-five million, one hundred eighty-nine thousand, eight hundred ninety-one".