21025011 has 8 divisors (see below), whose sum is σ = 32038144. Its totient is φ = 12014280.

The previous prime is 21024961. The next prime is 21025019. The reversal of 21025011 is 11052012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21025011 - 2⁹ = 21024499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21025019) 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 7 ways as a sum of consecutive naturals, for example, 500575 + ... + 500616.

It is an arithmetic number, because the mean of its divisors is an integer number (4004768).

Almost surely, 2^21025011 is an apocalyptic number.

21025011 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21025011 is a deficient number, since it is larger than the sum of its proper divisors (11013133).

21025011 is a wasteful number, since it uses less digits than its factorization.

21025011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1001201.

The product of its (nonzero) digits is 20, while the sum is 12.

The square root of 21025011 is about 4585.3038067286. The cubic root of 21025011 is about 276.0019034735.

Adding to 21025011 its reverse (11052012), we get a palindrome (32077023).

The spelling of 21025011 in words is "twenty-one million, twenty-five thousand, eleven".