51210201721 has 16 divisors (see below), whose sum is σ = 60819379200. Its totient is φ = 42193391040.

The previous prime is 51210201701. The next prime is 51210201743. The reversal of 51210201721 is 12710201215.

It is a cyclic number.

It is not a de Polignac number, because 51210201721 - 2³⁵ = 16850463353 is a prime.

It is a super-2 number, since 2×51210201721² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51210201692 and 51210201701.

It is not an unprimeable number, because it can be changed into a prime (51210201701) 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, 759586 + ... + 824251.

It is an arithmetic number, because the mean of its divisors is an integer number (3801211200).

Almost surely, 2^51210201721 is an apocalyptic number.

It is an amenable number.

51210201721 is a deficient number, since it is larger than the sum of its proper divisors (9609177479).

51210201721 is a wasteful number, since it uses less digits than its factorization.

51210201721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1584024.

The product of its (nonzero) digits is 280, while the sum is 22.

Adding to 51210201721 its reverse (12710201215), we get a palindrome (63920402936).

The spelling of 51210201721 in words is "fifty-one billion, two hundred ten million, two hundred one thousand, seven hundred twenty-one".