21684248612 has 24 divisors (see below), whose sum is σ = 43270380216. Its totient is φ = 9419401728.

The previous prime is 21684248569. The next prime is 21684248647.

21684248612 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 7488479296 + 14195769316 = 86536^2 + 119146^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12263963 + ... + 12265730.

It is an arithmetic number, because the mean of its divisors is an integer number (1802932509).

Almost surely, 2^21684248612 is an apocalyptic number.

It is an amenable number.

21684248612 is a deficient number, since it is larger than the sum of its proper divisors (21586131604).

21684248612 is a wasteful number, since it uses less digits than its factorization.

21684248612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24529727 (or 24529725 counting only the distinct ones).

The product of its digits is 294912, while the sum is 44.

The spelling of 21684248612 in words is "twenty-one billion, six hundred eighty-four million, two hundred forty-eight thousand, six hundred twelve".