21167144 has 8 divisors (see below), whose sum is σ = 39688410. Its totient is φ = 10583568.

The previous prime is 21167143. The next prime is 21167147. The reversal of 21167144 is 44176112.

It can be written as a sum of positive squares in only one way, i.e., 18062500 + 3104644 = 4250^2 + 1762^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (21167143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1322939 + ... + 1322954.

Almost surely, 2^21167144 is an apocalyptic number.

It is an amenable number.

21167144 is a deficient number, since it is larger than the sum of its proper divisors (18521266).

21167144 is a wasteful number, since it uses less digits than its factorization.

21167144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2645899 (or 2645895 counting only the distinct ones).

The product of its digits is 1344, while the sum is 26.

The square root of 21167144 is about 4600.7764562082. The cubic root of 21167144 is about 276.6224487001.

The spelling of 21167144 in words is "twenty-one million, one hundred sixty-seven thousand, one hundred forty-four".