145388491 has 4 divisors (see below), whose sum is σ = 145611792. Its totient is φ = 145165192.

The previous prime is 145388483. The next prime is 145388549. The reversal of 145388491 is 194883541.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 194883541 = 2411 ⋅80831.

It is a cyclic number.

It is not a de Polignac number, because 145388491 - 2³ = 145388483 is a prime.

It is a super-2 number, since 2×145388491² = 42275626630514162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (145388291) 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, 110671 + ... + 111976.

It is an arithmetic number, because the mean of its divisors is an integer number (36402948).

Almost surely, 2^145388491 is an apocalyptic number.

145388491 is a deficient number, since it is larger than the sum of its proper divisors (223301).

145388491 is an equidigital number, since it uses as much as digits as its factorization.

145388491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223300.

The product of its digits is 138240, while the sum is 43.

The square root of 145388491 is about 12057.7149991199. The cubic root of 145388491 is about 525.8275577224.

The spelling of 145388491 in words is "one hundred forty-five million, three hundred eighty-eight thousand, four hundred ninety-one".