51251645 has 16 divisors (see below), whose sum is σ = 65568000. Its totient is φ = 38346048.

The previous prime is 51251639. The next prime is 51251647. The reversal of 51251645 is 54615215.

It is a happy number.

51251645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 51251645 - 2⁶ = 51251581 is a prime.

It is a super-2 number, since 2×51251645² = 5253462230412050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51251647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4091 + ... + 10919.

It is an arithmetic number, because the mean of its divisors is an integer number (4098000).

Almost surely, 2^51251645 is an apocalyptic number.

It is an amenable number.

51251645 is a deficient number, since it is larger than the sum of its proper divisors (14316355).

51251645 is a wasteful number, since it uses less digits than its factorization.

51251645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6932.

The product of its digits is 6000, while the sum is 29.

The square root of 51251645 is about 7159.0254224999. The cubic root of 51251645 is about 371.4519162208.

The spelling of 51251645 in words is "fifty-one million, two hundred fifty-one thousand, six hundred forty-five".