21473964 has 24 divisors (see below), whose sum is σ = 55673520. Its totient is φ = 7157952.

The previous prime is 21473953. The next prime is 21473987. The reversal of 21473964 is 46937412.

It is a super-2 number, since 2×21473964² = 922262259746592, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a plaindrome in base 16.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 99309 + ... + 99524.

It is an arithmetic number, because the mean of its divisors is an integer number (2319730).

Almost surely, 2^21473964 is an apocalyptic number.

It is an amenable number.

21473964 is an abundant number, since it is smaller than the sum of its proper divisors (34199556).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21473964 is a wasteful number, since it uses less digits than its factorization.

21473964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198846 (or 198838 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 21473964 is about 4634.0008631851. Note that the first 3 decimals coincide. The cubic root of 21473964 is about 277.9525996165.

The spelling of 21473964 in words is "twenty-one million, four hundred seventy-three thousand, nine hundred sixty-four".