168621031 has 2 divisors, whose sum is σ = 168621032. Its totient is φ = 168621030.

The previous prime is 168621023. The next prime is 168621049. The reversal of 168621031 is 130126861.

It is a weak prime.

It is an emirp because it is prime and its reverse (130126861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 168621031 - 2³ = 168621023 is a prime.

It is a super-2 number, since 2×168621031² = 56866104191005922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168621001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84310515 + 84310516.

It is an arithmetic number, because the mean of its divisors is an integer number (84310516).

Almost surely, 2^168621031 is an apocalyptic number.

168621031 is a deficient number, since it is larger than the sum of its proper divisors (1).

168621031 is an equidigital number, since it uses as much as digits as its factorization.

168621031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 168621031 is about 12985.4160888283. The cubic root of 168621031 is about 552.4639108850.

Adding to 168621031 its reverse (130126861), we get a palindrome (298747892).

The spelling of 168621031 in words is "one hundred sixty-eight million, six hundred twenty-one thousand, thirty-one".