22321991 has 2 divisors, whose sum is σ = 22321992. Its totient is φ = 22321990.

The previous prime is 22321961. The next prime is 22321997. The reversal of 22321991 is 19912322.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 22321991 - 2⁶ = 22321927 is a prime.

It is a super-3 number, since 3×22321991³ (a number of 23 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22321997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11160995 + 11160996.

It is an arithmetic number, because the mean of its divisors is an integer number (11160996).

Almost surely, 2^22321991 is an apocalyptic number.

22321991 is a deficient number, since it is larger than the sum of its proper divisors (1).

22321991 is an equidigital number, since it uses as much as digits as its factorization.

22321991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944, while the sum is 29.

The square root of 22321991 is about 4724.6154340856. The cubic root of 22321991 is about 281.5643349113.

The spelling of 22321991 in words is "twenty-two million, three hundred twenty-one thousand, nine hundred ninety-one".