16253561 has 2 divisors, whose sum is σ = 16253562. Its totient is φ = 16253560.

The previous prime is 16253557. The next prime is 16253593. The reversal of 16253561 is 16535261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12075625 + 4177936 = 3475^2 + 2044^2 .

It is a cyclic number.

It is not a de Polignac number, because 16253561 - 2² = 16253557 is a prime.

It is not a weakly prime, because it can be changed into another prime (16253761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8126780 + 8126781.

It is an arithmetic number, because the mean of its divisors is an integer number (8126781).

Almost surely, 2^16253561 is an apocalyptic number.

It is an amenable number.

16253561 is a deficient number, since it is larger than the sum of its proper divisors (1).

16253561 is an equidigital number, since it uses as much as digits as its factorization.

16253561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5400, while the sum is 29.

The square root of 16253561 is about 4031.5705376441. The cubic root of 16253561 is about 253.3083514531.

It can be divided in two parts, 16 and 253561, that multiplied together give a triangular number (4056976 = T₂₈₄₈).

The spelling of 16253561 in words is "sixteen million, two hundred fifty-three thousand, five hundred sixty-one".