21053011 has 4 divisors (see below), whose sum is σ = 24060592. Its totient is φ = 18045432.

The previous prime is 21053009. The next prime is 21053017. The reversal of 21053011 is 11035012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21053011 - 2¹ = 21053009 is a prime.

It is a super-2 number, since 2×21053011² = 886458544332242, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21052982 and 21053000.

It is not an unprimeable number, because it can be changed into a prime (21053017) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1503780 + ... + 1503793.

It is an arithmetic number, because the mean of its divisors is an integer number (6015148).

Almost surely, 2^21053011 is an apocalyptic number.

21053011 is a deficient number, since it is larger than the sum of its proper divisors (3007581).

21053011 is an equidigital number, since it uses as much as digits as its factorization.

21053011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3007580.

The product of its (nonzero) digits is 30, while the sum is 13.

The square root of 21053011 is about 4588.3560236756. The cubic root of 21053011 is about 276.1243707139.

Adding to 21053011 its reverse (11035012), we get a palindrome (32088023).

The spelling of 21053011 in words is "twenty-one million, fifty-three thousand, eleven".