145188691 has 4 divisors (see below), whose sum is σ = 145767384. Its totient is φ = 144610000.

The previous prime is 145188679. The next prime is 145188731. The reversal of 145188691 is 196881541.

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 145188691 - 2⁹ = 145188179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (145188661) 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, 288970 + ... + 289471.

It is an arithmetic number, because the mean of its divisors is an integer number (36441846).

Almost surely, 2^145188691 is an apocalyptic number.

145188691 is a deficient number, since it is larger than the sum of its proper divisors (578693).

145188691 is an equidigital number, since it uses as much as digits as its factorization.

145188691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 578692.

The product of its digits is 69120, while the sum is 43.

The square root of 145188691 is about 12049.4269988245. The cubic root of 145188691 is about 525.5865746192.

The spelling of 145188691 in words is "one hundred forty-five million, one hundred eighty-eight thousand, six hundred ninety-one".