51512021 has 8 divisors (see below), whose sum is σ = 59152800. Its totient is φ = 44364240.

The previous prime is 51512011. The next prime is 51512039. The reversal of 51512021 is 12021515.

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

It is not a de Polignac number, because 51512021 - 2¹⁴ = 51495637 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 (51512011) 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, 123026 + ... + 123443.

It is an arithmetic number, because the mean of its divisors is an integer number (7394100).

Almost surely, 2^51512021 is an apocalyptic number.

It is an amenable number.

51512021 is a deficient number, since it is larger than the sum of its proper divisors (7640779).

51512021 is a wasteful number, since it uses less digits than its factorization.

51512021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246499.

The product of its (nonzero) digits is 100, while the sum is 17.

The square root of 51512021 is about 7177.1875410916. The cubic root of 51512021 is about 372.0798885155.

Adding to 51512021 its reverse (12021515), we get a palindrome (63533536).

The spelling of 51512021 in words is "fifty-one million, five hundred twelve thousand, twenty-one".