21033988 has 12 divisors (see below), whose sum is σ = 38746960. Its totient is φ = 9963432.

The previous prime is 21033979. The next prime is 21033989. The reversal of 21033988 is 88933012.

It is not an unprimeable number, because it can be changed into a prime (21033989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 138306 + ... + 138457.

Almost surely, 2^21033988 is an apocalyptic number.

It is an amenable number.

21033988 is a deficient number, since it is larger than the sum of its proper divisors (17712972).

21033988 is a wasteful number, since it uses less digits than its factorization.

21033988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276786 (or 276784 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 21033988 is about 4586.2825905084. The cubic root of 21033988 is about 276.0411791810.

The spelling of 21033988 in words is "twenty-one million, thirty-three thousand, nine hundred eighty-eight".