351389981 has 2 divisors, whose sum is σ = 351389982. Its totient is φ = 351389980.

The previous prime is 351389923. The next prime is 351389993. The reversal of 351389981 is 189983153.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 208802500 + 142587481 = 14450^2 + 11941^2 .

It is an emirp because it is prime and its reverse (189983153) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 351389981 - 2⁶ = 351389917 is a prime.

It is a super-2 number, since 2×351389981² = 246949837494360722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (351389281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 175694990 + 175694991.

It is an arithmetic number, because the mean of its divisors is an integer number (175694991).

Almost surely, 2^351389981 is an apocalyptic number.

It is an amenable number.

351389981 is a deficient number, since it is larger than the sum of its proper divisors (1).

351389981 is an equidigital number, since it uses as much as digits as its factorization.

351389981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 233280, while the sum is 47.

The square root of 351389981 is about 18745.3989288038. The cubic root of 351389981 is about 705.6615563043.

The spelling of 351389981 in words is "three hundred fifty-one million, three hundred eighty-nine thousand, nine hundred eighty-one".