53999999981 has 2 divisors, whose sum is σ = 53999999982. Its totient is φ = 53999999980.

The previous prime is 53999999957. The next prime is 54000000023. The reversal of 53999999981 is 18999999935.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29504932900 + 24495067081 = 171770^2 + 156509^2 .

It is a cyclic number.

It is not a de Polignac number, because 53999999981 - 2⁶ = 53999999917 is a prime.

It is a super-2 number, since 2×53999999981² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 53999999896 and 53999999905.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (53999999941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26999999990 + 26999999991.

It is an arithmetic number, because the mean of its divisors is an integer number (26999999991).

Almost surely, 2^53999999981 is an apocalyptic number.

It is an amenable number.

53999999981 is a deficient number, since it is larger than the sum of its proper divisors (1).

53999999981 is an equidigital number, since it uses as much as digits as its factorization.

53999999981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 573956280, while the sum is 80.

The spelling of 53999999981 in words is "fifty-three billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred eighty-one".