167521261 has 2 divisors, whose sum is σ = 167521262. Its totient is φ = 167521260.

The previous prime is 167521223. The next prime is 167521283. The reversal of 167521261 is 162125761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 144144036 + 23377225 = 12006^2 + 4835^2 .

It is a cyclic number.

It is not a de Polignac number, because 167521261 - 2¹⁷ = 167390189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (167521201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83760630 + 83760631.

It is an arithmetic number, because the mean of its divisors is an integer number (83760631).

Almost surely, 2^167521261 is an apocalyptic number.

It is an amenable number.

167521261 is a deficient number, since it is larger than the sum of its proper divisors (1).

167521261 is an equidigital number, since it uses as much as digits as its factorization.

167521261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 31.

The square root of 167521261 is about 12943.0004635710. Note that the first 3 decimals coincide. The cubic root of 167521261 is about 551.2602078176.

The spelling of 167521261 in words is "one hundred sixty-seven million, five hundred twenty-one thousand, two hundred sixty-one".