55973967781 has 2 divisors, whose sum is σ = 55973967782. Its totient is φ = 55973967780.

The previous prime is 55973967773. The next prime is 55973967787. The reversal of 55973967781 is 18776937955.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49671036900 + 6302930881 = 222870^2 + 79391^2 .

It is a cyclic number.

It is not a de Polignac number, because 55973967781 - 2³ = 55973967773 is a prime.

It is a super-2 number, since 2×55973967781² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55973967787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27986983890 + 27986983891.

It is an arithmetic number, because the mean of its divisors is an integer number (27986983891).

Almost surely, 2^55973967781 is an apocalyptic number.

It is an amenable number.

55973967781 is a deficient number, since it is larger than the sum of its proper divisors (1).

55973967781 is an equidigital number, since it uses as much as digits as its factorization.

55973967781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 100018800, while the sum is 67.

The spelling of 55973967781 in words is "fifty-five billion, nine hundred seventy-three million, nine hundred sixty-seven thousand, seven hundred eighty-one".