21101984 has 12 divisors (see below), whose sum is σ = 41544594. Its totient is φ = 10550976.

The previous prime is 21101963. The next prime is 21102023. The reversal of 21101984 is 48910112.

It can be written as a sum of positive squares in only one way, i.e., 13104400 + 7997584 = 3620^2 + 2828^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 329687 + ... + 329750.

Almost surely, 2^21101984 is an apocalyptic number.

It is an amenable number.

21101984 is a deficient number, since it is larger than the sum of its proper divisors (20442610).

21101984 is an equidigital number, since it uses as much as digits as its factorization.

21101984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 659447 (or 659439 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 21101984 is about 4593.6895846367. The cubic root of 21101984 is about 276.3383095023.

The spelling of 21101984 in words is "twenty-one million, one hundred one thousand, nine hundred eighty-four".