54697781 has 2 divisors, whose sum is σ = 54697782. Its totient is φ = 54697780.

The previous prime is 54697777. The next prime is 54697817. The reversal of 54697781 is 18779645.

Together with next prime (54697817) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 45900625 + 8797156 = 6775^2 + 2966^2 .

It is a cyclic number.

It is not a de Polignac number, because 54697781 - 2² = 54697777 is a prime.

It is a super-2 number, since 2×54697781² = 5983694492647922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (54697711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27348890 + 27348891.

It is an arithmetic number, because the mean of its divisors is an integer number (27348891).

Almost surely, 2^54697781 is an apocalyptic number.

54697781 is the 3308-th centered decagonal number.

It is an amenable number.

54697781 is a deficient number, since it is larger than the sum of its proper divisors (1).

54697781 is an equidigital number, since it uses as much as digits as its factorization.

54697781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 423360, while the sum is 47.

The square root of 54697781 is about 7395.7948186791. The cubic root of 54697781 is about 379.5974060293.

The spelling of 54697781 in words is "fifty-four million, six hundred ninety-seven thousand, seven hundred eighty-one".