21480164 has 6 divisors (see below), whose sum is σ = 37590294. Its totient is φ = 10740080.

The previous prime is 21480161. The next prime is 21480167. The reversal of 21480164 is 46108412.

It is an interprime number because it is at equal distance from previous prime (21480161) and next prime (21480167).

It can be written as a sum of positive squares in only one way, i.e., 21436900 + 43264 = 4630^2 + 208^2 .

It is a super-2 number, since 2×21480164² = 922794890933792, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21480161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2685017 + ... + 2685024.

It is an arithmetic number, because the mean of its divisors is an integer number (6265049).

Almost surely, 2^21480164 is an apocalyptic number.

It is an amenable number.

21480164 is a deficient number, since it is larger than the sum of its proper divisors (16110130).

21480164 is a wasteful number, since it uses less digits than its factorization.

21480164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5370045 (or 5370043 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 21480164 is about 4634.6697832747. The cubic root of 21480164 is about 277.9793473607.

Adding to 21480164 its reverse (46108412), we get a palindrome (67588576).

The spelling of 21480164 in words is "twenty-one million, four hundred eighty thousand, one hundred sixty-four".