51415421 has 4 divisors (see below), whose sum is σ = 51469344. Its totient is φ = 51361500.

The previous prime is 51415379. The next prime is 51415447. The reversal of 51415421 is 12451415.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12451415 = 5 ⋅2490283.

It is a cyclic number.

It is not a de Polignac number, because 51415421 - 2¹⁴ = 51399037 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51415451) 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, 25505 + ... + 27446.

It is an arithmetic number, because the mean of its divisors is an integer number (12867336).

Almost surely, 2^51415421 is an apocalyptic number.

It is an amenable number.

51415421 is a deficient number, since it is larger than the sum of its proper divisors (53923).

51415421 is an equidigital number, since it uses as much as digits as its factorization.

51415421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53922.

The product of its digits is 800, while the sum is 23.

The square root of 51415421 is about 7170.4547275609. The cubic root of 51415421 is about 371.8471570237.

Adding to 51415421 its reverse (12451415), we get a palindrome (63866836).

The spelling of 51415421 in words is "fifty-one million, four hundred fifteen thousand, four hundred twenty-one".