145331561 has 4 divisors (see below), whose sum is σ = 146476032. Its totient is φ = 144187092.

The previous prime is 145331507. The next prime is 145331569. The reversal of 145331561 is 165133541.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 165133541 = 19 ⋅8691239.

It is a cyclic number.

It is not a de Polignac number, because 145331561 - 2⁶ = 145331497 is a prime.

It is a super-2 number, since 2×145331561² = 42242525245393442, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (145331569) 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, 572045 + ... + 572298.

It is an arithmetic number, because the mean of its divisors is an integer number (36619008).

Almost surely, 2^145331561 is an apocalyptic number.

It is an amenable number.

145331561 is a deficient number, since it is larger than the sum of its proper divisors (1144471).

145331561 is a wasteful number, since it uses less digits than its factorization.

145331561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1144470.

The product of its digits is 5400, while the sum is 29.

The square root of 145331561 is about 12055.3540387663. The cubic root of 145331561 is about 525.7589157210.

The spelling of 145331561 in words is "one hundred forty-five million, three hundred thirty-one thousand, five hundred sixty-one".