21487696 has 20 divisors (see below), whose sum is σ = 42205012. Its totient is φ = 10596096.

The previous prime is 21487693. The next prime is 21487699. The reversal of 21487696 is 69678412.

It is an interprime number because it is at equal distance from previous prime (21487693) and next prime (21487699).

It can be written as a sum of positive squares in 2 ways, for example, as 16289296 + 5198400 = 4036^2 + 2280^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21487693) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8031 + ... + 10366.

Almost surely, 2^21487696 is an apocalyptic number.

It is an amenable number.

21487696 is a deficient number, since it is larger than the sum of its proper divisors (20717316).

21487696 is a wasteful number, since it uses less digits than its factorization.

21487696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18478 (or 18472 counting only the distinct ones).

The product of its digits is 145152, while the sum is 43.

The square root of 21487696 is about 4635.4822834307. The cubic root of 21487696 is about 278.0118346324.

The spelling of 21487696 in words is "twenty-one million, four hundred eighty-seven thousand, six hundred ninety-six".