55453781 has 2 divisors, whose sum is σ = 55453782. Its totient is φ = 55453780.

The previous prime is 55453763. The next prime is 55453817. The reversal of 55453781 is 18735455.

Together with next prime (55453817) 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., 51251281 + 4202500 = 7159^2 + 2050^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55453781 is a prime.

It is a super-2 number, since 2×55453781² = 6150243654391922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55453721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27726890 + 27726891.

It is an arithmetic number, because the mean of its divisors is an integer number (27726891).

Almost surely, 2^55453781 is an apocalyptic number.

It is an amenable number.

55453781 is a deficient number, since it is larger than the sum of its proper divisors (1).

55453781 is an equidigital number, since it uses as much as digits as its factorization.

55453781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 84000, while the sum is 38.

The square root of 55453781 is about 7446.7295506148. The cubic root of 55453781 is about 381.3382661887.

The spelling of 55453781 in words is "fifty-five million, four hundred fifty-three thousand, seven hundred eighty-one".