21052461 has 4 divisors (see below), whose sum is σ = 28069952. Its totient is φ = 14034972.

The previous prime is 21052411. The next prime is 21052469. The reversal of 21052461 is 16425012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21052461 - 2⁷ = 21052333 is a prime.

It is a super-2 number, since 2×21052461² = 886412228313042, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21052469) 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 3 ways as a sum of consecutive naturals, for example, 3508741 + ... + 3508746.

It is an arithmetic number, because the mean of its divisors is an integer number (7017488).

Almost surely, 2^21052461 is an apocalyptic number.

It is an amenable number.

21052461 is a deficient number, since it is larger than the sum of its proper divisors (7017491).

21052461 is an equidigital number, since it uses as much as digits as its factorization.

21052461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7017490.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 21052461 is about 4588.2960889637. The cubic root of 21052461 is about 276.1219661533.

Adding to 21052461 its reverse (16425012), we get a palindrome (37477473).

The spelling of 21052461 in words is "twenty-one million, fifty-two thousand, four hundred sixty-one".