21542167 has 2 divisors, whose sum is σ = 21542168. Its totient is φ = 21542166.

The previous prime is 21542161. The next prime is 21542173. The reversal of 21542167 is 76124512.

It is a balanced prime because it is at equal distance from previous prime (21542161) and next prime (21542173).

It is a cyclic number.

It is not a de Polignac number, because 21542167 - 2³ = 21542159 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21542161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10771083 + 10771084.

It is an arithmetic number, because the mean of its divisors is an integer number (10771084).

Almost surely, 2^21542167 is an apocalyptic number.

21542167 is a deficient number, since it is larger than the sum of its proper divisors (1).

21542167 is an equidigital number, since it uses as much as digits as its factorization.

21542167 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3360, while the sum is 28.

The square root of 21542167 is about 4641.3540050291. The cubic root of 21542167 is about 278.2465550724.

Adding to 21542167 its reverse (76124512), we get a palindrome (97666679).

The spelling of 21542167 in words is "twenty-one million, five hundred forty-two thousand, one hundred sixty-seven".