45665621 has 4 divisors (see below), whose sum is σ = 48351852. Its totient is φ = 42979392.

The previous prime is 45665611. The next prime is 45665629. The reversal of 45665621 is 12656654.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12656654 = 2 ⋅6328327.

It can be written as a sum of positive squares in 2 ways, for example, as 17522596 + 28143025 = 4186^2 + 5305^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-45665621 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 (45665629) 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, 1343090 + ... + 1343123.

It is an arithmetic number, because the mean of its divisors is an integer number (12087963).

Almost surely, 2^45665621 is an apocalyptic number.

It is an amenable number.

45665621 is a deficient number, since it is larger than the sum of its proper divisors (2686231).

45665621 is a wasteful number, since it uses less digits than its factorization.

45665621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2686230.

The product of its digits is 43200, while the sum is 35.

The square root of 45665621 is about 6757.6342753955. The cubic root of 45665621 is about 357.4344894388.

The spelling of 45665621 in words is "forty-five million, six hundred sixty-five thousand, six hundred twenty-one".