21000316 has 6 divisors (see below), whose sum is σ = 36750560. Its totient is φ = 10500156.

The previous prime is 21000313. The next prime is 21000337. The reversal of 21000316 is 61300012.

It is a junction number, because it is equal to n+sod(n) for n = 21000296 and 21000305.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2625036 + ... + 2625043.

Almost surely, 2^21000316 is an apocalyptic number.

It is an amenable number.

21000316 is a deficient number, since it is larger than the sum of its proper divisors (15750244).

21000316 is a wasteful number, since it uses less digits than its factorization.

21000316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5250083 (or 5250081 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21000316 is about 4582.6101732528. The cubic root of 21000316 is about 275.8938014725.

Adding to 21000316 its reverse (61300012), we get a palindrome (82300328).

It can be divided in two parts, 21000 and 316, that added together give a square (21316 = 146²).

The spelling of 21000316 in words is "twenty-one million, three hundred sixteen", and thus it is an aban number.