51517021 has 16 divisors (see below), whose sum is σ = 57153600. Its totient is φ = 46213888.

The previous prime is 51517019. The next prime is 51517031. The reversal of 51517021 is 12071515.

It is not a de Polignac number, because 51517021 - 2¹ = 51517019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51516983 and 51517001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51517031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40290 + ... + 41548.

It is an arithmetic number, because the mean of its divisors is an integer number (3572100).

Almost surely, 2^51517021 is an apocalyptic number.

It is an amenable number.

51517021 is a deficient number, since it is larger than the sum of its proper divisors (5636579).

51517021 is a wasteful number, since it uses less digits than its factorization.

51517021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1388.

The product of its (nonzero) digits is 350, while the sum is 22.

The square root of 51517021 is about 7177.5358584963. The cubic root of 51517021 is about 372.0919267363.

Adding to 51517021 its reverse (12071515), we get a palindrome (63588536).

The spelling of 51517021 in words is "fifty-one million, five hundred seventeen thousand, twenty-one".