53561087981 has 2 divisors, whose sum is σ = 53561087982. Its totient is φ = 53561087980.

The previous prime is 53561087969. The next prime is 53561088013. The reversal of 53561087981 is 18978016535.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50845740100 + 2715347881 = 225490^2 + 52109^2 .

It is a cyclic number.

It is not a de Polignac number, because 53561087981 - 2⁶ = 53561087917 is a prime.

It is a super-2 number, since 2×53561087981² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (53561087911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26780543990 + 26780543991.

It is an arithmetic number, because the mean of its divisors is an integer number (26780543991).

Almost surely, 2^53561087981 is an apocalyptic number.

It is an amenable number.

53561087981 is a deficient number, since it is larger than the sum of its proper divisors (1).

53561087981 is an equidigital number, since it uses as much as digits as its factorization.

53561087981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1814400, while the sum is 53.

The spelling of 53561087981 in words is "fifty-three billion, five hundred sixty-one million, eighty-seven thousand, nine hundred eighty-one".