145613561 has 4 divisors (see below), whose sum is σ = 145768272. Its totient is φ = 145458852.

The previous prime is 145613557. The next prime is 145613563. The reversal of 145613561 is 165316541.

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: 165316541 = 13 ⋅12716657.

It is a cyclic number.

It is not a de Polignac number, because 145613561 - 2² = 145613557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (145613563) 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, 75935 + ... + 77828.

It is an arithmetic number, because the mean of its divisors is an integer number (36442068).

Almost surely, 2^145613561 is an apocalyptic number.

It is an amenable number.

145613561 is a deficient number, since it is larger than the sum of its proper divisors (154711).

145613561 is an equidigital number, since it uses as much as digits as its factorization.

145613561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154710.

The product of its digits is 10800, while the sum is 32.

The square root of 145613561 is about 12067.0444185807. The cubic root of 145613561 is about 526.0987552341.

The spelling of 145613561 in words is "one hundred forty-five million, six hundred thirteen thousand, five hundred sixty-one".