33661420021 has 2 divisors, whose sum is σ = 33661420022. Its totient is φ = 33661420020.

The previous prime is 33661419941. The next prime is 33661420031. The reversal of 33661420021 is 12002416633.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20273772996 + 13387647025 = 142386^2 + 115705^2 .

It is a cyclic number.

It is not a de Polignac number, because 33661420021 - 2¹¹ = 33661417973 is a prime.

It is a super-2 number, since 2×33661420021² (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 (33661420031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16830710010 + 16830710011.

It is an arithmetic number, because the mean of its divisors is an integer number (16830710011).

Almost surely, 2^33661420021 is an apocalyptic number.

It is an amenable number.

33661420021 is a deficient number, since it is larger than the sum of its proper divisors (1).

33661420021 is an equidigital number, since it uses as much as digits as its factorization.

33661420021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 28.

Adding to 33661420021 its reverse (12002416633), we get a palindrome (45663836654).

The spelling of 33661420021 in words is "thirty-three billion, six hundred sixty-one million, four hundred twenty thousand, twenty-one".