221853377491 has 2 divisors, whose sum is σ = 221853377492. Its totient is φ = 221853377490.

The previous prime is 221853377489. The next prime is 221853377579. The reversal of 221853377491 is 194773358122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221853377491 - 2¹ = 221853377489 is a prime.

It is a super-2 number, since 2×221853377491² (a number of 23 digits) contains 22 as substring.

Together with 221853377489, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (221853377461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110926688745 + 110926688746.

It is an arithmetic number, because the mean of its divisors is an integer number (110926688746).

Almost surely, 2^221853377491 is an apocalyptic number.

221853377491 is a deficient number, since it is larger than the sum of its proper divisors (1).

221853377491 is an equidigital number, since it uses as much as digits as its factorization.

221853377491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2540160, while the sum is 52.

The spelling of 221853377491 in words is "two hundred twenty-one billion, eight hundred fifty-three million, three hundred seventy-seven thousand, four hundred ninety-one".