54456781 has 2 divisors, whose sum is σ = 54456782. Its totient is φ = 54456780.

The previous prime is 54456761. The next prime is 54456799. The reversal of 54456781 is 18765445.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54022500 + 434281 = 7350^2 + 659^2 .

It is a cyclic number.

It is not a de Polignac number, because 54456781 - 2⁵ = 54456749 is a prime.

It is a super-2 number, since 2×54456781² = 5931081993763922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (54456761) 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, 27228390 + 27228391.

It is an arithmetic number, because the mean of its divisors is an integer number (27228391).

Almost surely, 2^54456781 is an apocalyptic number.

54456781 is the 3945-th centered heptagonal number.

It is an amenable number.

54456781 is a deficient number, since it is larger than the sum of its proper divisors (1).

54456781 is an equidigital number, since it uses as much as digits as its factorization.

54456781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 134400, while the sum is 40.

The square root of 54456781 is about 7379.4837895343. The cubic root of 54456781 is about 379.0390795189.

The spelling of 54456781 in words is "fifty-four million, four hundred fifty-six thousand, seven hundred eighty-one".