145505999 has 4 divisors (see below), whose sum is σ = 145536864. Its totient is φ = 145475136.

The previous prime is 145505993. The next prime is 145506001. The reversal of 145505999 is 999505541.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 999505541 = 6277 ⋅159233.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-145505999 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 (145505993) 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, 6722 + ... + 18335.

It is an arithmetic number, because the mean of its divisors is an integer number (36384216).

Almost surely, 2^145505999 is an apocalyptic number.

145505999 is a deficient number, since it is larger than the sum of its proper divisors (30865).

145505999 is an equidigital number, since it uses as much as digits as its factorization.

145505999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30864.

The product of its (nonzero) digits is 364500, while the sum is 47.

The square root of 145505999 is about 12062.5867458021. The cubic root of 145505999 is about 525.9691835715.

The spelling of 145505999 in words is "one hundred forty-five million, five hundred five thousand, nine hundred ninety-nine".