21116404 has 12 divisors (see below), whose sum is σ = 36987300. Its totient is φ = 10548608.

The previous prime is 21116401. The next prime is 21116411. The reversal of 21116404 is 40461112.

It can be written as a sum of positive squares in 2 ways, for example, as 12236004 + 8880400 = 3498^2 + 2980^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21116401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5292 + ... + 8380.

It is an arithmetic number, because the mean of its divisors is an integer number (3082275).

Almost surely, 2^21116404 is an apocalyptic number.

It is an amenable number.

21116404 is a deficient number, since it is larger than the sum of its proper divisors (15870896).

21116404 is a wasteful number, since it uses less digits than its factorization.

21116404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4802 (or 4800 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 21116404 is about 4595.2588610436. The cubic root of 21116404 is about 276.4012402532.

Adding to 21116404 its reverse (40461112), we get a palindrome (61577516).

It can be divided in two parts, 2111 and 6404, that added together give a triangular number (8515 = T₁₃₀).

The spelling of 21116404 in words is "twenty-one million, one hundred sixteen thousand, four hundred four".