51206121 has 16 divisors (see below), whose sum is σ = 79854400. Its totient is φ = 32340384.

The previous prime is 51206117. The next prime is 51206131. The reversal of 51206121 is 12160215.

51206121 is a `hidden beast` number, since 51 + 2 + 0 + 612 + 1 = 666.

It is not a de Polignac number, because 51206121 - 2² = 51206117 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51206094 and 51206103.

It is not an unprimeable number, because it can be changed into a prime (51206101) 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, 49396 + ... + 50421.

It is an arithmetic number, because the mean of its divisors is an integer number (4990900).

Almost surely, 2^51206121 is an apocalyptic number.

It is an amenable number.

51206121 is a deficient number, since it is larger than the sum of its proper divisors (28648279).

51206121 is a wasteful number, since it uses less digits than its factorization.

51206121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99845 (or 99839 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 51206121 is about 7155.8452330944. The cubic root of 51206121 is about 371.3419035813.

Adding to 51206121 its reverse (12160215), we get a palindrome (63366336).

The spelling of 51206121 in words is "fifty-one million, two hundred six thousand, one hundred twenty-one".