51025221021 has 32 divisors (see below), whose sum is σ = 71124579328. Its totient is φ = 32512233600.

The previous prime is 51025220977. The next prime is 51025221041. The reversal of 51025221021 is 12012252015.

It is not a de Polignac number, because 51025221021 - 2¹⁰ = 51025219997 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 (51025221041) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1285545 + ... + 1324641.

It is an arithmetic number, because the mean of its divisors is an integer number (2222643104).

Almost surely, 2^51025221021 is an apocalyptic number.

It is an amenable number.

51025221021 is a deficient number, since it is larger than the sum of its proper divisors (20099358307).

51025221021 is a wasteful number, since it uses less digits than its factorization.

51025221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39361.

The product of its (nonzero) digits is 400, while the sum is 21.

Adding to 51025221021 its reverse (12012252015), we get a palindrome (63037473036).

The spelling of 51025221021 in words is "fifty-one billion, twenty-five million, two hundred twenty-one thousand, twenty-one".