55125439981 has 2 divisors, whose sum is σ = 55125439982. Its totient is φ = 55125439980.

The previous prime is 55125439933. The next prime is 55125439991. The reversal of 55125439981 is 18993452155.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28021086025 + 27104353956 = 167395^2 + 164634^2 .

It is a cyclic number.

It is not a de Polignac number, because 55125439981 - 2¹³ = 55125431789 is a prime.

It is a super-2 number, since 2×55125439981² (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 (55125439991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27562719990 + 27562719991.

It is an arithmetic number, because the mean of its divisors is an integer number (27562719991).

Almost surely, 2^55125439981 is an apocalyptic number.

It is an amenable number.

55125439981 is a deficient number, since it is larger than the sum of its proper divisors (1).

55125439981 is an equidigital number, since it uses as much as digits as its factorization.

55125439981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1944000, while the sum is 52.

The spelling of 55125439981 in words is "fifty-five billion, one hundred twenty-five million, four hundred thirty-nine thousand, nine hundred eighty-one".