21709108 has 12 divisors (see below), whose sum is σ = 38327940. Its totient is φ = 10758272.

The previous prime is 21709099. The next prime is 21709117. The reversal of 21709108 is 80190712.

It is an interprime number because it is at equal distance from previous prime (21709099) and next prime (21709117).

It can be written as a sum of positive squares in 2 ways, for example, as 4169764 + 17539344 = 2042^2 + 4188^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23563 + ... + 24466.

It is an arithmetic number, because the mean of its divisors is an integer number (3193995).

Almost surely, 2^21709108 is an apocalyptic number.

It is an amenable number.

21709108 is a deficient number, since it is larger than the sum of its proper divisors (16618832).

21709108 is a wasteful number, since it uses less digits than its factorization.

21709108 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48146 (or 48144 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 21709108 is about 4659.3033814080. The cubic root of 21709108 is about 278.9634634821.

The spelling of 21709108 in words is "twenty-one million, seven hundred nine thousand, one hundred eight".