167881621 has 2 divisors, whose sum is σ = 167881622. Its totient is φ = 167881620.

The previous prime is 167881591. The next prime is 167881631. The reversal of 167881621 is 126188761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 144937521 + 22944100 = 12039^2 + 4790^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-167881621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (167881631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83940810 + 83940811.

It is an arithmetic number, because the mean of its divisors is an integer number (83940811).

Almost surely, 2^167881621 is an apocalyptic number.

It is an amenable number.

167881621 is a deficient number, since it is larger than the sum of its proper divisors (1).

167881621 is an equidigital number, since it uses as much as digits as its factorization.

167881621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32256, while the sum is 40.

The square root of 167881621 is about 12956.9140230226. The cubic root of 167881621 is about 551.6552021706.

The spelling of 167881621 in words is "one hundred sixty-seven million, eight hundred eighty-one thousand, six hundred twenty-one".