21147036 has 24 divisors (see below), whose sum is σ = 49969920. Its totient is φ = 6959472.

The previous prime is 21147029. The next prime is 21147037. The reversal of 21147036 is 63074112.

It is a junction number, because it is equal to n+sod(n) for n = 21146997 and 21147015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21147037) 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, 10206 + ... + 12101.

It is an arithmetic number, because the mean of its divisors is an integer number (2082080).

Almost surely, 2^21147036 is an apocalyptic number.

It is an amenable number.

21147036 is an abundant number, since it is smaller than the sum of its proper divisors (28822884).

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

21147036 is a wasteful number, since it uses less digits than its factorization.

21147036 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22393 (or 22391 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21147036 is about 4598.5906536677. The cubic root of 21147036 is about 276.5348272672.

The spelling of 21147036 in words is "twenty-one million, one hundred forty-seven thousand, thirty-six".