21241988 has 6 divisors (see below), whose sum is σ = 37173486. Its totient is φ = 10620992.

The previous prime is 21241973. The next prime is 21241991. The reversal of 21241988 is 88914212.

It can be written as a sum of positive squares in only one way, i.e., 20720704 + 521284 = 4552^2 + 722^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2655245 + ... + 2655252.

It is an arithmetic number, because the mean of its divisors is an integer number (6195581).

Almost surely, 2^21241988 is an apocalyptic number.

It is an amenable number.

21241988 is a deficient number, since it is larger than the sum of its proper divisors (15931498).

21241988 is a wasteful number, since it uses less digits than its factorization.

21241988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5310501 (or 5310499 counting only the distinct ones).

The product of its digits is 9216, while the sum is 35.

The square root of 21241988 is about 4608.9031233039. The cubic root of 21241988 is about 276.9480976838.

The spelling of 21241988 in words is "twenty-one million, two hundred forty-one thousand, nine hundred eighty-eight".