53106721 has 2 divisors, whose sum is σ = 53106722. Its totient is φ = 53106720.

The previous prime is 53106719. The next prime is 53106727. The reversal of 53106721 is 12760135.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32901696 + 20205025 = 5736^2 + 4495^2 .

It is a cyclic number.

It is not a de Polignac number, because 53106721 - 2¹ = 53106719 is a prime.

Together with 53106719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (53106727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26553360 + 26553361.

It is an arithmetic number, because the mean of its divisors is an integer number (26553361).

Almost surely, 2^53106721 is an apocalyptic number.

It is an amenable number.

53106721 is a deficient number, since it is larger than the sum of its proper divisors (1).

53106721 is an equidigital number, since it uses as much as digits as its factorization.

53106721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 53106721 is about 7287.4358316214. The cubic root of 53106721 is about 375.8805287586.

Adding to 53106721 its reverse (12760135), we get a palindrome (65866856).

The spelling of 53106721 in words is "fifty-three million, one hundred six thousand, seven hundred twenty-one".