21447136 has 12 divisors (see below), whose sum is σ = 42224112. Its totient is φ = 10723552.

The previous prime is 21447119. The next prime is 21447137. The reversal of 21447136 is 63174412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21447137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 335080 + ... + 335143.

It is an arithmetic number, because the mean of its divisors is an integer number (3518676).

Almost surely, 2^21447136 is an apocalyptic number.

It is an amenable number.

21447136 is a deficient number, since it is larger than the sum of its proper divisors (20776976).

21447136 is an equidigital number, since it uses as much as digits as its factorization.

21447136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 670233 (or 670225 counting only the distinct ones).

The product of its digits is 4032, while the sum is 28.

The square root of 21447136 is about 4631.1052676440. The cubic root of 21447136 is about 277.8368001632.

The spelling of 21447136 in words is "twenty-one million, four hundred forty-seven thousand, one hundred thirty-six".