21033887 has 12 divisors (see below), whose sum is σ = 24603480. Its totient is φ = 17929296.

The previous prime is 21033877. The next prime is 21033907. The reversal of 21033887 is 78833012.

It is not a de Polignac number, because 21033887 - 2⁶ = 21033823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033827) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8564 + ... + 10742.

It is an arithmetic number, because the mean of its divisors is an integer number (2050290).

Almost surely, 2^21033887 is an apocalyptic number.

21033887 is a deficient number, since it is larger than the sum of its proper divisors (3569593).

21033887 is a wasteful number, since it uses less digits than its factorization.

21033887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2390 (or 2383 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 21033887 is about 4586.2715793987. The cubic root of 21033887 is about 276.0407373531.

Adding to 21033887 its reverse (78833012), we get a palindrome (99866899).

The spelling of 21033887 in words is "twenty-one million, thirty-three thousand, eight hundred eighty-seven".