51004421 has 4 divisors (see below), whose sum is σ = 54927852. Its totient is φ = 47080992.

The previous prime is 51004381. The next prime is 51004423. The reversal of 51004421 is 12440015.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15124321 + 35880100 = 3889^2 + 5990^2 .

It is a cyclic number.

It is not a de Polignac number, because 51004421 - 2¹⁴ = 50988037 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 51004421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51004423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1961696 + ... + 1961721.

It is an arithmetic number, because the mean of its divisors is an integer number (13731963).

Almost surely, 2^51004421 is an apocalyptic number.

It is an amenable number.

51004421 is a deficient number, since it is larger than the sum of its proper divisors (3923431).

51004421 is a wasteful number, since it uses less digits than its factorization.

51004421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3923430.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 51004421 is about 7141.7379537477. The cubic root of 51004421 is about 370.8536922824.

Adding to 51004421 its reverse (12440015), we get a palindrome (63444436).

The spelling of 51004421 in words is "fifty-one million, four thousand, four hundred twenty-one".