54909781 has 2 divisors, whose sum is σ = 54909782. Its totient is φ = 54909780.

The previous prime is 54909733. The next prime is 54909793. The reversal of 54909781 is 18790945.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54908100 + 1681 = 7410^2 + 41^2 .

It is a cyclic number.

It is not a de Polignac number, because 54909781 - 2⁷ = 54909653 is a prime.

It is a super-2 number, since 2×54909781² = 6030168098935922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (54909721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27454890 + 27454891.

It is an arithmetic number, because the mean of its divisors is an integer number (27454891).

Almost surely, 2^54909781 is an apocalyptic number.

It is an amenable number.

54909781 is a deficient number, since it is larger than the sum of its proper divisors (1).

54909781 is an equidigital number, since it uses as much as digits as its factorization.

54909781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 54909781 is about 7410.1134269321. The cubic root of 54909781 is about 380.0871937493.

The spelling of 54909781 in words is "fifty-four million, nine hundred nine thousand, seven hundred eighty-one".