33491667721 has 2 divisors, whose sum is σ = 33491667722. Its totient is φ = 33491667720.

The previous prime is 33491667673. The next prime is 33491667743. The reversal of 33491667721 is 12776619433.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 32629364496 + 862303225 = 180636^2 + 29365^2 .

It is a cyclic number.

It is not a de Polignac number, because 33491667721 - 2²³ = 33483279113 is a prime.

It is a super-2 number, since 2×33491667721² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (33491667761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16745833860 + 16745833861.

It is an arithmetic number, because the mean of its divisors is an integer number (16745833861).

Almost surely, 2^33491667721 is an apocalyptic number.

It is an amenable number.

33491667721 is a deficient number, since it is larger than the sum of its proper divisors (1).

33491667721 is an equidigital number, since it uses as much as digits as its factorization.

33491667721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1143072, while the sum is 49.

The spelling of 33491667721 in words is "thirty-three billion, four hundred ninety-one million, six hundred sixty-seven thousand, seven hundred twenty-one".