45161721 has 24 divisors (see below), whose sum is σ = 71413056. Its totient is φ = 27275040.

The previous prime is 45161681. The next prime is 45161723. The reversal of 45161721 is 12716154.

It is a happy number.

45161721 is a `hidden beast` number, since 45 + 1 + 617 + 2 + 1 = 666.

It is not a de Polignac number, because 45161721 - 2⁹ = 45161209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (45161723) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 36316 + ... + 37538.

It is an arithmetic number, because the mean of its divisors is an integer number (2975544).

Almost surely, 2^45161721 is an apocalyptic number.

It is an amenable number.

45161721 is a deficient number, since it is larger than the sum of its proper divisors (26251335).

45161721 is a wasteful number, since it uses less digits than its factorization.

45161721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1613 (or 1610 counting only the distinct ones).

The product of its digits is 1680, while the sum is 27.

The square root of 45161721 is about 6720.2470936715. The cubic root of 45161721 is about 356.1149131410.

Adding to 45161721 its reverse (12716154), we get a palindrome (57877875).

The spelling of 45161721 in words is "forty-five million, one hundred sixty-one thousand, seven hundred twenty-one".