51240421 has 8 divisors (see below), whose sum is σ = 51655680. Its totient is φ = 50827392.

The previous prime is 51240407. The next prime is 51240433. The reversal of 51240421 is 12404215.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51240421 - 2²³ = 42851813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51240451) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 133596 + ... + 133978.

It is an arithmetic number, because the mean of its divisors is an integer number (6456960).

Almost surely, 2^51240421 is an apocalyptic number.

It is an amenable number.

51240421 is a deficient number, since it is larger than the sum of its proper divisors (415259).

51240421 is a wasteful number, since it uses less digits than its factorization.

51240421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1115.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 51240421 is about 7158.2414739935. The cubic root of 51240421 is about 371.4247985176.

Adding to 51240421 its reverse (12404215), we get a palindrome (63644636).

The spelling of 51240421 in words is "fifty-one million, two hundred forty thousand, four hundred twenty-one".