21034020 has 96 divisors (see below), whose sum is σ = 68495616. Its totient is φ = 4723200.

The previous prime is 21034003. The next prime is 21034033. The reversal of 21034020 is 2043012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21033987 and 21034005.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25210 + ... + 26030.

It is an arithmetic number, because the mean of its divisors is an integer number (713496).

Almost surely, 2^21034020 is an apocalyptic number.

21034020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21034020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34247808).

21034020 is an abundant number, since it is smaller than the sum of its proper divisors (47461596).

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

21034020 is a wasteful number, since it uses less digits than its factorization.

21034020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 901 (or 899 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 21034020 is about 4586.2860791713. The cubic root of 21034020 is about 276.0413191657.

Adding to 21034020 its reverse (2043012), we get a palindrome (23077032).

The spelling of 21034020 in words is "twenty-one million, thirty-four thousand, twenty".