37817255981 has 2 divisors, whose sum is σ = 37817255982. Its totient is φ = 37817255980.

The previous prime is 37817255921. The next prime is 37817256011. The reversal of 37817255981 is 18955271873.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23368013956 + 14449242025 = 152866^2 + 120205^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-37817255981 is a prime.

It is a super-2 number, since 2×37817255981² (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 (37817255921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18908627990 + 18908627991.

It is an arithmetic number, because the mean of its divisors is an integer number (18908627991).

Almost surely, 2^37817255981 is an apocalyptic number.

It is an amenable number.

37817255981 is a deficient number, since it is larger than the sum of its proper divisors (1).

37817255981 is an equidigital number, since it uses as much as digits as its factorization.

37817255981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4233600, while the sum is 56.

The spelling of 37817255981 in words is "thirty-seven billion, eight hundred seventeen million, two hundred fifty-five thousand, nine hundred eighty-one".