50640021 has 24 divisors (see below), whose sum is σ = 74580480. Its totient is φ = 33105600.

The previous prime is 50640011. The next prime is 50640049. The reversal of 50640021 is 12004605.

It is a happy number.

50640021 is a `hidden beast` number, since 5 + 0 + 640 + 0 + 21 = 666.

It is not a de Polignac number, because 50640021 - 2⁷ = 50639893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 50639976 and 50640003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (50640011) 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 23 ways as a sum of consecutive naturals, for example, 152826 + ... + 153156.

It is an arithmetic number, because the mean of its divisors is an integer number (3107520).

Almost surely, 2^50640021 is an apocalyptic number.

It is an amenable number.

50640021 is a deficient number, since it is larger than the sum of its proper divisors (23940459).

50640021 is a wasteful number, since it uses less digits than its factorization.

50640021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 617 (or 614 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 50640021 is about 7116.1802253737. The cubic root of 50640021 is about 369.9683951578.

Adding to 50640021 its reverse (12004605), we get a palindrome (62644626).

The spelling of 50640021 in words is "fifty million, six hundred forty thousand, twenty-one".