51550640 has 20 divisors (see below), whose sum is σ = 119855424. Its totient is φ = 20620224.

The previous prime is 51550637. The next prime is 51550643. The reversal of 51550640 is 4605515.

It is an interprime number because it is at equal distance from previous prime (51550637) and next prime (51550643).

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (51550643) 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 3 ways as a sum of consecutive naturals, for example, 322112 + ... + 322271.

Almost surely, 2^51550640 is an apocalyptic number.

It is an amenable number.

51550640 is an abundant number, since it is smaller than the sum of its proper divisors (68304784).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51550640 is a wasteful number, since it uses less digits than its factorization.

51550640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 644396 (or 644390 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 26.

The square root of 51550640 is about 7179.8774362798. The cubic root of 51550640 is about 372.1728491066.

The spelling of 51550640 in words is "fifty-one million, five hundred fifty thousand, six hundred forty".