9953557510661 has 2 divisors, whose sum is σ = 9953557510662. Its totient is φ = 9953557510660.

The previous prime is 9953557510657. The next prime is 9953557510691. The reversal of 9953557510661 is 1660157553599.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5725640194561 + 4227917316100 = 2392831^2 + 2056190^2 .

It is a cyclic number.

It is not a de Polignac number, because 9953557510661 - 2² = 9953557510657 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 9953557510594 and 9953557510603.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9953557510691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4976778755330 + 4976778755331.

It is an arithmetic number, because the mean of its divisors is an integer number (4976778755331).

Almost surely, 2^{9953557510661} is an apocalyptic number.

It is an amenable number.

9953557510661 is a deficient number, since it is larger than the sum of its proper divisors (1).

9953557510661 is an equidigital number, since it uses as much as digits as its factorization.

9953557510661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38272500, while the sum is 62.

The spelling of 9953557510661 in words is "nine trillion, nine hundred fifty-three billion, five hundred fifty-seven million, five hundred ten thousand, six hundred sixty-one".