21472816 has 10 divisors (see below), whose sum is σ = 41603612. Its totient is φ = 10736400.

The previous prime is 21472813. The next prime is 21472817. The reversal of 21472816 is 61827412.

21472816 is nontrivially palindromic in base 3.

It is a super-2 number, since 2×21472816² = 922163653939712, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21472813) 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, 671010 + ... + 671041.

Almost surely, 2^21472816 is an apocalyptic number.

It is an amenable number.

21472816 is a deficient number, since it is larger than the sum of its proper divisors (20130796).

21472816 is a wasteful number, since it uses less digits than its factorization.

21472816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1342059 (or 1342053 counting only the distinct ones).

The product of its digits is 5376, while the sum is 31.

The square root of 21472816 is about 4633.8769944831. The cubic root of 21472816 is about 277.9476464047.

The spelling of 21472816 in words is "twenty-one million, four hundred seventy-two thousand, eight hundred sixteen".