167917921 has 2 divisors, whose sum is σ = 167917922. Its totient is φ = 167917920.

The previous prime is 167917909. The next prime is 167917957. The reversal of 167917921 is 129719761.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 129960000 + 37957921 = 11400^2 + 6161^2 .

It is an emirp because it is prime and its reverse (129719761) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 167917921 - 2¹⁵ = 167885153 is a prime.

It is not a weakly prime, because it can be changed into another prime (167911921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83958960 + 83958961.

It is an arithmetic number, because the mean of its divisors is an integer number (83958961).

Almost surely, 2^167917921 is an apocalyptic number.

It is an amenable number.

167917921 is a deficient number, since it is larger than the sum of its proper divisors (1).

167917921 is an equidigital number, since it uses as much as digits as its factorization.

167917921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 47628, while the sum is 43.

The square root of 167917921 is about 12958.3147438238. The cubic root of 167917921 is about 551.6949596310.

It can be divided in two parts, 1679 and 17921, that added together give a square (19600 = 140²).

The spelling of 167917921 in words is "one hundred sixty-seven million, nine hundred seventeen thousand, nine hundred twenty-one".