21004116 has 24 divisors (see below), whose sum is σ = 56011200. Its totient is φ = 6001152.

The previous prime is 21004099. The next prime is 21004117. The reversal of 21004116 is 61140012.

It is a junction number, because it is equal to n+sod(n) for n = 21004095 and 21004104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21004117) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 124941 + ... + 125108.

It is an arithmetic number, because the mean of its divisors is an integer number (2333800).

Almost surely, 2^21004116 is an apocalyptic number.

It is an amenable number.

21004116 is an abundant number, since it is smaller than the sum of its proper divisors (35007084).

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

21004116 is a wasteful number, since it uses less digits than its factorization.

21004116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250063 (or 250061 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 21004116 is about 4583.0247653706. The cubic root of 21004116 is about 275.9104414319.

Adding to 21004116 its reverse (61140012), we get a palindrome (82144128).

It can be divided in two parts, 2100 and 4116, that multiplied together give a square (8643600 = 2940²).

The spelling of 21004116 in words is "twenty-one million, four thousand, one hundred sixteen".