21034881 has 24 divisors (see below), whose sum is σ = 36553920. Its totient is φ = 11386656.

The previous prime is 21034861. The next prime is 21034891. The reversal of 21034881 is 18843012.

It is not a de Polignac number, because 21034881 - 2⁹ = 21034369 is a prime.

It is a super-2 number, since 2×21034881² = 884932437368322, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21034861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7590 + ... + 9983.

It is an arithmetic number, because the mean of its divisors is an integer number (1523080).

Almost surely, 2^21034881 is an apocalyptic number.

21034881 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21034881 is a deficient number, since it is larger than the sum of its proper divisors (15519039).

21034881 is a wasteful number, since it uses less digits than its factorization.

21034881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17605 (or 17602 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 21034881 is about 4586.3799450111. The cubic root of 21034881 is about 276.0450855774.

Adding to 21034881 its reverse (18843012), we get a palindrome (39877893).

The spelling of 21034881 in words is "twenty-one million, thirty-four thousand, eight hundred eighty-one".