21034920 has 32 divisors (see below), whose sum is σ = 63105120. Its totient is φ = 5609280.

The previous prime is 21034891. The next prime is 21034943. The reversal of 21034920 is 2943012.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87526 + ... + 87765.

It is an arithmetic number, because the mean of its divisors is an integer number (1972035).

Almost surely, 2^21034920 is an apocalyptic number.

21034920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21034920 is an abundant number, since it is smaller than the sum of its proper divisors (42070200).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21034920 is a wasteful number, since it uses less digits than its factorization.

21034920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175305 (or 175301 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 21034920 is about 4586.3841967284. The cubic root of 21034920 is about 276.0452561789.

Adding to 21034920 its reverse (2943012), we get a palindrome (23977932).

The spelling of 21034920 in words is "twenty-one million, thirty-four thousand, nine hundred twenty".