33638399981 has 2 divisors, whose sum is σ = 33638399982. Its totient is φ = 33638399980.

The previous prime is 33638399929. The next prime is 33638400001. The reversal of 33638399981 is 18999383633.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33029791081 + 608608900 = 181741^2 + 24670^2 .

It is a cyclic number.

It is not a de Polignac number, because 33638399981 - 2⁶ = 33638399917 is a prime.

It is a super-2 number, since 2×33638399981² (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 (33638393981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16819199990 + 16819199991.

It is an arithmetic number, because the mean of its divisors is an integer number (16819199991).

Almost surely, 2^33638399981 is an apocalyptic number.

It is an amenable number.

33638399981 is a deficient number, since it is larger than the sum of its proper divisors (1).

33638399981 is an equidigital number, since it uses as much as digits as its factorization.

33638399981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22674816, while the sum is 62.

The spelling of 33638399981 in words is "thirty-three billion, six hundred thirty-eight million, three hundred ninety-nine thousand, nine hundred eighty-one".