221916031 has 2 divisors, whose sum is σ = 221916032. Its totient is φ = 221916030.

The previous prime is 221916017. The next prime is 221916049. The reversal of 221916031 is 130619122.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221916031 is a prime.

It is a super-2 number, since 2×221916031² = 98493449629585922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221915987 and 221916005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221916731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110958015 + 110958016.

It is an arithmetic number, because the mean of its divisors is an integer number (110958016).

Almost surely, 2^221916031 is an apocalyptic number.

221916031 is a deficient number, since it is larger than the sum of its proper divisors (1).

221916031 is an equidigital number, since it uses as much as digits as its factorization.

221916031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 221916031 is about 14896.8463441092. The cubic root of 221916031 is about 605.4285432214.

The spelling of 221916031 in words is "two hundred twenty-one million, nine hundred sixteen thousand, thirty-one".