51644109 has 32 divisors (see below), whose sum is σ = 81653760. Its totient is φ = 28684800.

The previous prime is 51644107. The next prime is 51644111. The reversal of 51644109 is 90144615.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (51644107) and next prime (51644111).

It is not a de Polignac number, because 51644109 - 2¹ = 51644107 is a prime.

It is a super-2 number, since 2×51644109² = 5334227988807762, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51644107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18109 + ... + 20765.

It is an arithmetic number, because the mean of its divisors is an integer number (2551680).

Almost surely, 2^51644109 is an apocalyptic number.

It is an amenable number.

51644109 is a deficient number, since it is larger than the sum of its proper divisors (30009651).

51644109 is a wasteful number, since it uses less digits than its factorization.

51644109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2721.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 51644109 is about 7186.3835828600. The cubic root of 51644109 is about 372.3976482604.

The spelling of 51644109 in words is "fifty-one million, six hundred forty-four thousand, one hundred nine".