51824721 has 16 divisors (see below), whose sum is σ = 78793344. Its totient is φ = 30015744.

The previous prime is 51824719. The next prime is 51824767. The reversal of 51824721 is 12742815.

It is not a de Polignac number, because 51824721 - 2¹ = 51824719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51824021) 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 15 ways as a sum of consecutive naturals, for example, 38421 + ... + 39746.

It is an arithmetic number, because the mean of its divisors is an integer number (4924584).

Almost surely, 2^51824721 is an apocalyptic number.

51824721 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

51824721 is a deficient number, since it is larger than the sum of its proper divisors (26968623).

51824721 is a wasteful number, since it uses less digits than its factorization.

51824721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78200.

The product of its digits is 4480, while the sum is 30.

The square root of 51824721 is about 7198.9388801406. The cubic root of 51824721 is about 372.8312648577.

The spelling of 51824721 in words is "fifty-one million, eight hundred twenty-four thousand, seven hundred twenty-one".