54451981 has 2 divisors, whose sum is σ = 54451982. Its totient is φ = 54451980.

The previous prime is 54451973. The next prime is 54451987. The reversal of 54451981 is 18915445.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49829481 + 4622500 = 7059^2 + 2150^2 .

It is a cyclic number.

It is not a de Polignac number, because 54451981 - 2³ = 54451973 is a prime.

It is a super-2 number, since 2×54451981² = 5930036469648722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 54451981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (54451987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27225990 + 27225991.

It is an arithmetic number, because the mean of its divisors is an integer number (27225991).

Almost surely, 2^54451981 is an apocalyptic number.

It is an amenable number.

54451981 is a deficient number, since it is larger than the sum of its proper divisors (1).

54451981 is an equidigital number, since it uses as much as digits as its factorization.

54451981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28800, while the sum is 37.

The square root of 54451981 is about 7379.1585563667. The cubic root of 54451981 is about 379.0279426074.

It can be divided in two parts, 544 and 51981, that added together give a palindrome (52525).

The spelling of 54451981 in words is "fifty-four million, four hundred fifty-one thousand, nine hundred eighty-one".