21020760 has 48 divisors (see below), whose sum is σ = 68318640. Its totient is φ = 5605440.

The previous prime is 21020749. The next prime is 21020761. The reversal of 21020760 is 6702012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28836 + ... + 29555.

It is an arithmetic number, because the mean of its divisors is an integer number (1423305).

Almost surely, 2^21020760 is an apocalyptic number.

21020760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21020760 is an abundant number, since it is smaller than the sum of its proper divisors (47297880).

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

21020760 is a wasteful number, since it uses less digits than its factorization.

21020760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58408 (or 58401 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 21020760 is about 4584.8402371293. The cubic root of 21020760 is about 275.9833008170.

Adding to 21020760 its reverse (6702012), we get a palindrome (27722772).

The spelling of 21020760 in words is "twenty-one million, twenty thousand, seven hundred sixty".