145495991 has 4 divisors (see below), whose sum is σ = 145634184. Its totient is φ = 145357800.

The previous prime is 145495981. The next prime is 145495993. The reversal of 145495991 is 199594541.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 199594541 = 67 ⋅2979023.

It is a cyclic number.

It is not a de Polignac number, because 145495991 - 2¹⁰ = 145494967 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 (145495993) 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, 67505 + ... + 69626.

It is an arithmetic number, because the mean of its divisors is an integer number (36408546).

Almost surely, 2^145495991 is an apocalyptic number.

145495991 is a deficient number, since it is larger than the sum of its proper divisors (138193).

145495991 is a wasteful number, since it uses less digits than its factorization.

145495991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138192.

The product of its digits is 291600, while the sum is 47.

The square root of 145495991 is about 12062.1719022737. The cubic root of 145495991 is about 525.9571244575.

The spelling of 145495991 in words is "one hundred forty-five million, four hundred ninety-five thousand, nine hundred ninety-one".