51445645 has 4 divisors (see below), whose sum is σ = 61734780. Its totient is φ = 41156512.

The previous prime is 51445643. The next prime is 51445661. The reversal of 51445645 is 54654415.

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 32592681 + 18852964 = 5709^2 + 4342^2 .

It is a cyclic number.

It is not a de Polignac number, because 51445645 - 2¹ = 51445643 is a prime.

It is a super-3 number, since 3×51445645³ (a number of 24 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 51445645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51445643) 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, 5144560 + ... + 5144569.

It is an arithmetic number, because the mean of its divisors is an integer number (15433695).

Almost surely, 2^51445645 is an apocalyptic number.

It is an amenable number.

51445645 is a deficient number, since it is larger than the sum of its proper divisors (10289135).

51445645 is a wasteful number, since it uses less digits than its factorization.

51445645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10289134.

The product of its digits is 48000, while the sum is 34.

The square root of 51445645 is about 7172.5619551176. The cubic root of 51445645 is about 371.9200048632.

The spelling of 51445645 in words is "fifty-one million, four hundred forty-five thousand, six hundred forty-five".