145953991 has 4 divisors (see below), whose sum is σ = 153635800. Its totient is φ = 138272184.

The previous prime is 145953971. The next prime is 145954009. The reversal of 145953991 is 199359541.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 199359541 = 97 ⋅2055253.

It is a cyclic number.

It is not a de Polignac number, because 145953991 - 2¹¹ = 145951943 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 (145953901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3840876 + ... + 3840913.

It is an arithmetic number, because the mean of its divisors is an integer number (38408950).

Almost surely, 2^145953991 is an apocalyptic number.

145953991 is a deficient number, since it is larger than the sum of its proper divisors (7681809).

145953991 is an equidigital number, since it uses as much as digits as its factorization.

145953991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7681808.

The product of its digits is 218700, while the sum is 46.

The square root of 145953991 is about 12081.1419576131. The cubic root of 145953991 is about 526.5084249712.

The spelling of 145953991 in words is "one hundred forty-five million, nine hundred fifty-three thousand, nine hundred ninety-one".