51107921 has 2 divisors, whose sum is σ = 51107922. Its totient is φ = 51107920.

The previous prime is 51107911. The next prime is 51107939. The reversal of 51107921 is 12970115.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48094225 + 3013696 = 6935^2 + 1736^2 .

It is a cyclic number.

It is not a de Polignac number, because 51107921 - 2⁶ = 51107857 is a prime.

It is a super-2 number, since 2×51107921² = 5224039177884482, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51107911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25553960 + 25553961.

It is an arithmetic number, because the mean of its divisors is an integer number (25553961).

Almost surely, 2^51107921 is an apocalyptic number.

It is an amenable number.

51107921 is a deficient number, since it is larger than the sum of its proper divisors (1).

51107921 is an equidigital number, since it uses as much as digits as its factorization.

51107921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 630, while the sum is 26.

The square root of 51107921 is about 7148.9804168147. The cubic root of 51107921 is about 371.1043726657.

It can be divided in two parts, 5110 and 7921, that added together give a palindrome (13031).

The spelling of 51107921 in words is "fifty-one million, one hundred seven thousand, nine hundred twenty-one".