145545551 has 4 divisors (see below), whose sum is σ = 154107072. Its totient is φ = 136984032.

The previous prime is 145545509. The next prime is 145545581. The reversal of 145545551 is 155545541.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 155545541 = 307 ⋅506663.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-145545551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145545581) 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, 4280735 + ... + 4280768.

It is an arithmetic number, because the mean of its divisors is an integer number (38526768).

Almost surely, 2^145545551 is an apocalyptic number.

145545551 is a deficient number, since it is larger than the sum of its proper divisors (8561521).

145545551 is an equidigital number, since it uses as much as digits as its factorization.

145545551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8561520.

The product of its digits is 50000, while the sum is 35.

The square root of 145545551 is about 12064.2260837569. The cubic root of 145545551 is about 526.0168362425.

The spelling of 145545551 in words is "one hundred forty-five million, five hundred forty-five thousand, five hundred fifty-one".