221298731 has 2 divisors, whose sum is σ = 221298732. Its totient is φ = 221298730.

The previous prime is 221298713. The next prime is 221298751. The reversal of 221298731 is 137892122.

Together with previous prime (221298713) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221298731 - 2¹⁰ = 221297707 is a prime.

It is a super-2 number, since 2×221298731² = 97946256684420722, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 221298691 and 221298700.

It is not a weakly prime, because it can be changed into another prime (221298751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110649365 + 110649366.

It is an arithmetic number, because the mean of its divisors is an integer number (110649366).

Almost surely, 2^221298731 is an apocalyptic number.

221298731 is a deficient number, since it is larger than the sum of its proper divisors (1).

221298731 is an equidigital number, since it uses as much as digits as its factorization.

221298731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 35.

The square root of 221298731 is about 14876.1127651010. The cubic root of 221298731 is about 604.8666518485.

The spelling of 221298731 in words is "two hundred twenty-one million, two hundred ninety-eight thousand, seven hundred thirty-one".