21120416 has 12 divisors (see below), whose sum is σ = 41580882. Its totient is φ = 10560192.

The previous prime is 21120403. The next prime is 21120427. The reversal of 21120416 is 61402112.

It can be written as a sum of positive squares in only one way, i.e., 19324816 + 1795600 = 4396^2 + 1340^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21120394 and 21120403.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 329975 + ... + 330038.

Almost surely, 2^21120416 is an apocalyptic number.

It is an amenable number.

21120416 is a deficient number, since it is larger than the sum of its proper divisors (20460466).

21120416 is an equidigital number, since it uses as much as digits as its factorization.

21120416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 660023 (or 660015 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 21120416 is about 4595.6953771981. The cubic root of 21120416 is about 276.4187440472.

Adding to 21120416 its reverse (61402112), we get a palindrome (82522528).

The spelling of 21120416 in words is "twenty-one million, one hundred twenty thousand, four hundred sixteen".