145721945 has 4 divisors (see below), whose sum is σ = 174866340. Its totient is φ = 116577552.

The previous prime is 145721923. The next prime is 145721957. The reversal of 145721945 is 549127541.

145721945 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 549127541 = 53 ⋅10360897.

It can be written as a sum of positive squares in 2 ways, for example, as 18731584 + 126990361 = 4328^2 + 11269^2 .

It is a cyclic number.

It is not a de Polignac number, because 145721945 - 2⁶ = 145721881 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 145721899 and 145721908.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14572190 + ... + 14572199.

It is an arithmetic number, because the mean of its divisors is an integer number (43716585).

Almost surely, 2^145721945 is an apocalyptic number.

It is an amenable number.

145721945 is a deficient number, since it is larger than the sum of its proper divisors (29144395).

145721945 is an equidigital number, since it uses as much as digits as its factorization.

145721945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29144394.

The product of its digits is 50400, while the sum is 38.

The square root of 145721945 is about 12071.5344923502. The cubic root of 145721945 is about 526.2292525715.

The spelling of 145721945 in words is "one hundred forty-five million, seven hundred twenty-one thousand, nine hundred forty-five".