21301020 has 72 divisors (see below), whose sum is σ = 69590976. Its totient is φ = 5242752.

The previous prime is 21300997. The next prime is 21301031. The reversal of 21301020 is 2010312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 21300993 and 21301011.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2212 + ... + 6891.

Almost surely, 2^21301020 is an apocalyptic number.

21301020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21301020 is an abundant number, since it is smaller than the sum of its proper divisors (48289956).

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

21301020 is a wasteful number, since it uses less digits than its factorization.

21301020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9131 (or 9126 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 21301020 is about 4615.3028069673. The cubic root of 21301020 is about 277.2044088927.

Adding to 21301020 its reverse (2010312), we get a palindrome (23311332).

The spelling of 21301020 in words is "twenty-one million, three hundred one thousand, twenty".