346721981 has 2 divisors, whose sum is σ = 346721982. Its totient is φ = 346721980.

The previous prime is 346721951. The next prime is 346721993. The reversal of 346721981 is 189127643.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 296184100 + 50537881 = 17210^2 + 7109^2 .

It is a cyclic number.

It is not a de Polignac number, because 346721981 - 2¹⁸ = 346459837 is a prime.

It is a super-2 number, since 2×346721981² = 240432264217128722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (346721911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 173360990 + 173360991.

It is an arithmetic number, because the mean of its divisors is an integer number (173360991).

Almost surely, 2^346721981 is an apocalyptic number.

It is an amenable number.

346721981 is a deficient number, since it is larger than the sum of its proper divisors (1).

346721981 is an equidigital number, since it uses as much as digits as its factorization.

346721981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 41.

The square root of 346721981 is about 18620.4720939078. The cubic root of 346721981 is about 702.5228563630.

The spelling of 346721981 in words is "three hundred forty-six million, seven hundred twenty-one thousand, nine hundred eighty-one".