21164468 has 24 divisors (see below), whose sum is σ = 40034568. Its totient is φ = 9732096.

The previous prime is 21164459. The next prime is 21164477. The reversal of 21164468 is 86446112.

It is an interprime number because it is at equal distance from previous prime (21164459) and next prime (21164477).

It can be written as a sum of positive squares in 4 ways, for example, as 1909924 + 19254544 = 1382^2 + 4388^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17780 + ... + 18932.

It is an arithmetic number, because the mean of its divisors is an integer number (1668107).

Almost surely, 2^21164468 is an apocalyptic number.

It is an amenable number.

21164468 is a deficient number, since it is larger than the sum of its proper divisors (18870100).

21164468 is a wasteful number, since it uses less digits than its factorization.

21164468 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1523 (or 1521 counting only the distinct ones).

The product of its digits is 9216, while the sum is 32.

The square root of 21164468 is about 4600.4856265399. The cubic root of 21164468 is about 276.6107911226.

The spelling of 21164468 in words is "twenty-one million, one hundred sixty-four thousand, four hundred sixty-eight".