55637546421781 has 2 divisors, whose sum is σ = 55637546421782. Its totient is φ = 55637546421780.

The previous prime is 55637546421773. The next prime is 55637546421823. The reversal of 55637546421781 is 18712464573655.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40132655781156 + 15504890640625 = 6335034^2 + 3937625^2 .

It is a cyclic number.

It is not a de Polignac number, because 55637546421781 - 2³ = 55637546421773 is a prime.

It is a super-2 number, since 2×55637546421781² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55637546421701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27818773210890 + 27818773210891.

It is an arithmetic number, because the mean of its divisors is an integer number (27818773210891).

Almost surely, 2^{55637546421781} is an apocalyptic number.

It is an amenable number.

55637546421781 is a deficient number, since it is larger than the sum of its proper divisors (1).

55637546421781 is an equidigital number, since it uses as much as digits as its factorization.

55637546421781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 169344000, while the sum is 64.

The spelling of 55637546421781 in words is "fifty-five trillion, six hundred thirty-seven billion, five hundred forty-six million, four hundred twenty-one thousand, seven hundred eighty-one".