21147616 has 36 divisors (see below), whose sum is σ = 48435408. Its totient is φ = 9062592.

The previous prime is 21147601. The next prime is 21147617. The reversal of 21147616 is 61674112.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21147617) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5176 + ... + 8311.

It is an arithmetic number, because the mean of its divisors is an integer number (1345428).

Almost surely, 2^21147616 is an apocalyptic number.

It is an amenable number.

21147616 is an abundant number, since it is smaller than the sum of its proper divisors (27287792).

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

21147616 is a wasteful number, since it uses less digits than its factorization.

21147616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13511 (or 13496 counting only the distinct ones).

The product of its digits is 2016, while the sum is 28.

The square root of 21147616 is about 4598.6537160347. The cubic root of 21147616 is about 276.5373554188.

It can be divided in two parts, 2114 and 7616, that added together give a triangular number (9730 = T₁₃₉).

The spelling of 21147616 in words is "twenty-one million, one hundred forty-seven thousand, six hundred sixteen".