53509721 has 2 divisors, whose sum is σ = 53509722. Its totient is φ = 53509720.

The previous prime is 53509679. The next prime is 53509739. The reversal of 53509721 is 12790535.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51912025 + 1597696 = 7205^2 + 1264^2 .

It is a cyclic number.

It is not a de Polignac number, because 53509721 - 2¹⁸ = 53247577 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (53509741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26754860 + 26754861.

It is an arithmetic number, because the mean of its divisors is an integer number (26754861).

Almost surely, 2^53509721 is an apocalyptic number.

It is an amenable number.

53509721 is a deficient number, since it is larger than the sum of its proper divisors (1).

53509721 is an equidigital number, since it uses as much as digits as its factorization.

53509721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9450, while the sum is 32.

The square root of 53509721 is about 7315.0339028606. The cubic root of 53509721 is about 376.8289227945.

The spelling of 53509721 in words is "fifty-three million, five hundred nine thousand, seven hundred twenty-one".