51025010221 has 4 divisors (see below), whose sum is σ = 51530208444. Its totient is φ = 50519812000.

The previous prime is 51025010209. The next prime is 51025010237. The reversal of 51025010221 is 12201052015.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12201052015 = 5 ⋅2440210403.

It can be written as a sum of positive squares in 2 ways, for example, as 21568153321 + 29456856900 = 146861^2 + 171630^2 .

It is a cyclic number.

It is not a de Polignac number, because 51025010221 - 2⁵ = 51025010189 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 (51025010251) 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, 252598960 + ... + 252599161.

It is an arithmetic number, because the mean of its divisors is an integer number (12882552111).

Almost surely, 2^51025010221 is an apocalyptic number.

It is an amenable number.

51025010221 is a deficient number, since it is larger than the sum of its proper divisors (505198223).

51025010221 is a wasteful number, since it uses less digits than its factorization.

51025010221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505198222.

The product of its (nonzero) digits is 200, while the sum is 19.

Adding to 51025010221 its reverse (12201052015), we get a palindrome (63226062236).

The spelling of 51025010221 in words is "fifty-one billion, twenty-five million, ten thousand, two hundred twenty-one".