220421666551 has 2 divisors, whose sum is σ = 220421666552. Its totient is φ = 220421666550.

The previous prime is 220421666497. The next prime is 220421666627. The reversal of 220421666551 is 155666124022.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 220421666551 - 2⁹ = 220421666039 is a prime.

It is a super-2 number, since 2×220421666551² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (220421666351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110210833275 + 110210833276.

It is an arithmetic number, because the mean of its divisors is an integer number (110210833276).

Almost surely, 2^220421666551 is an apocalyptic number.

220421666551 is a deficient number, since it is larger than the sum of its proper divisors (1).

220421666551 is an equidigital number, since it uses as much as digits as its factorization.

220421666551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 172800, while the sum is 40.

The spelling of 220421666551 in words is "two hundred twenty billion, four hundred twenty-one million, six hundred sixty-six thousand, five hundred fifty-one".