45205257721 has 4 divisors (see below), whose sum is σ = 48682585252. Its totient is φ = 41727930192.

The previous prime is 45205257707. The next prime is 45205257733. The reversal of 45205257721 is 12775250254.

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 18354830400 + 26850427321 = 135480^2 + 163861^2 .

It is a de Polignac number, because none of the positive numbers 2^k-45205257721 is a prime.

It is a super-2 number, since 2×45205257721² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (45205257761) 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, 1738663746 + ... + 1738663771.

It is an arithmetic number, because the mean of its divisors is an integer number (12170646313).

Almost surely, 2^45205257721 is an apocalyptic number.

It is an amenable number.

45205257721 is a deficient number, since it is larger than the sum of its proper divisors (3477327531).

45205257721 is a wasteful number, since it uses less digits than its factorization.

45205257721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3477327530.

The product of its (nonzero) digits is 196000, while the sum is 40.

The spelling of 45205257721 in words is "forty-five billion, two hundred five million, two hundred fifty-seven thousand, seven hundred twenty-one".