21161164 has 6 divisors (see below), whose sum is σ = 37032044. Its totient is φ = 10580580.

The previous prime is 21161137. The next prime is 21161191. The reversal of 21161164 is 46116112.

It is an interprime number because it is at equal distance from previous prime (21161137) and next prime (21161191).

It is an unprimeable number.

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, 2645142 + ... + 2645149.

Almost surely, 2^21161164 is an apocalyptic number.

It is an amenable number.

21161164 is a deficient number, since it is larger than the sum of its proper divisors (15870880).

21161164 is a wasteful number, since it uses less digits than its factorization.

21161164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5290295 (or 5290293 counting only the distinct ones).

The product of its digits is 288, while the sum is 22.

The square root of 21161164 is about 4600.1265199992. The cubic root of 21161164 is about 276.5963964050.

Adding to 21161164 its reverse (46116112), we get a palindrome (67277276).

The spelling of 21161164 in words is "twenty-one million, one hundred sixty-one thousand, one hundred sixty-four".