221370731 has 2 divisors, whose sum is σ = 221370732. Its totient is φ = 221370730.

The previous prime is 221370713. The next prime is 221370739. The reversal of 221370731 is 137073122.

Together with previous prime (221370713) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221370731 - 2¹⁴ = 221354347 is a prime.

It is a super-2 number, since 2×221370731² = 98010001086948722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 221370731.

It is not a weakly prime, because it can be changed into another prime (221370739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110685365 + 110685366.

It is an arithmetic number, because the mean of its divisors is an integer number (110685366).

Almost surely, 2^221370731 is an apocalyptic number.

221370731 is a deficient number, since it is larger than the sum of its proper divisors (1).

221370731 is an equidigital number, since it uses as much as digits as its factorization.

221370731 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1764, while the sum is 26.

The square root of 221370731 is about 14878.5325553295. The cubic root of 221370731 is about 604.9322429412.

The spelling of 221370731 in words is "two hundred twenty-one million, three hundred seventy thousand, seven hundred thirty-one".