145305661 has 4 divisors (see below), whose sum is σ = 145334332. Its totient is φ = 145276992.

The previous prime is 145305637. The next prime is 145305691. The reversal of 145305661 is 166503541.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 139688761 + 5616900 = 11819^2 + 2370^2 .

It is a cyclic number.

It is not a de Polignac number, because 145305661 - 2¹³ = 145297469 is a prime.

It is a super-2 number, since 2×145305661² = 42227470237293842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145305691) 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, 4470 + ... + 17623.

It is an arithmetic number, because the mean of its divisors is an integer number (36333583).

Almost surely, 2^145305661 is an apocalyptic number.

It is an amenable number.

145305661 is a deficient number, since it is larger than the sum of its proper divisors (28671).

145305661 is an equidigital number, since it uses as much as digits as its factorization.

145305661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28670.

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 145305661 is about 12054.2797793979. The cubic root of 145305661 is about 525.7276814756.

The spelling of 145305661 in words is "one hundred forty-five million, three hundred five thousand, six hundred sixty-one".