51038821 has 2 divisors, whose sum is σ = 51038822. Its totient is φ = 51038820.

The previous prime is 51038773. The next prime is 51038831. The reversal of 51038821 is 12883015.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29052100 + 21986721 = 5390^2 + 4689^2 .

It is a cyclic number.

It is not a de Polignac number, because 51038821 - 2¹¹ = 51036773 is a prime.

It is a super-2 number, since 2×51038821² = 5209922498140082, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 51038821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51038831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25519410 + 25519411.

It is an arithmetic number, because the mean of its divisors is an integer number (25519411).

Almost surely, 2^51038821 is an apocalyptic number.

It is an amenable number.

51038821 is a deficient number, since it is larger than the sum of its proper divisors (1).

51038821 is an equidigital number, since it uses as much as digits as its factorization.

51038821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 51038821 is about 7144.1459251614. The cubic root of 51038821 is about 370.9370478018.

It can be divided in two parts, 5103 and 8821, that added together give a square (13924 = 118²).

The spelling of 51038821 in words is "fifty-one million, thirty-eight thousand, eight hundred twenty-one".