21167427 has 16 divisors (see below), whose sum is σ = 28990208. Its totient is φ = 13733280.

The previous prime is 21167423. The next prime is 21167467. The reversal of 21167427 is 72476112.

It is not a de Polignac number, because 21167427 - 2² = 21167423 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21167394 and 21167403.

It is not an unprimeable number, because it can be changed into a prime (21167423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18288 + ... + 19410.

It is an arithmetic number, because the mean of its divisors is an integer number (1811888).

Almost surely, 2^21167427 is an apocalyptic number.

21167427 is a deficient number, since it is larger than the sum of its proper divisors (7822781).

21167427 is a wasteful number, since it uses less digits than its factorization.

21167427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1290.

The product of its digits is 4704, while the sum is 30.

The square root of 21167427 is about 4600.8072117836. The cubic root of 21167427 is about 276.6236814881.

It can be divided in two parts, 21167 and 427, that multiplied together give a palindrome (9038309).

The spelling of 21167427 in words is "twenty-one million, one hundred sixty-seven thousand, four hundred twenty-seven".