33212578981 has 2 divisors, whose sum is σ = 33212578982. Its totient is φ = 33212578980.

The previous prime is 33212578967. The next prime is 33212578991. The reversal of 33212578981 is 18987521233.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21151048356 + 12061530625 = 145434^2 + 109825^2 .

It is an emirp because it is prime and its reverse (18987521233) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 33212578981 - 2¹¹ = 33212576933 is a prime.

It is a super-2 number, since 2×33212578981² (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 (33212578901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16606289490 + 16606289491.

It is an arithmetic number, because the mean of its divisors is an integer number (16606289491).

Almost surely, 2^33212578981 is an apocalyptic number.

It is an amenable number.

33212578981 is a deficient number, since it is larger than the sum of its proper divisors (1).

33212578981 is an equidigital number, since it uses as much as digits as its factorization.

33212578981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 725760, while the sum is 49.

The spelling of 33212578981 in words is "thirty-three billion, two hundred twelve million, five hundred seventy-eight thousand, nine hundred eighty-one".