21206696 has 16 divisors (see below), whose sum is σ = 45443040. Its totient is φ = 9088560.

The previous prime is 21206693. The next prime is 21206699. The reversal of 21206696 is 69660212.

It is an interprime number because it is at equal distance from previous prime (21206693) and next prime (21206699).

It is not an unprimeable number, because it can be changed into a prime (21206693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 189290 + ... + 189401.

It is an arithmetic number, because the mean of its divisors is an integer number (2840190).

Almost surely, 2^21206696 is an apocalyptic number.

It is an amenable number.

21206696 is an abundant number, since it is smaller than the sum of its proper divisors (24236344).

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

21206696 is a wasteful number, since it uses less digits than its factorization.

21206696 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378704 (or 378700 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 21206696 is about 4605.0728550154. The cubic root of 21206696 is about 276.7946363691.

The spelling of 21206696 in words is "twenty-one million, two hundred six thousand, six hundred ninety-six".