21141621 has 8 divisors (see below), whose sum is σ = 31320960. Its totient is φ = 14094396.

The previous prime is 21141611. The next prime is 21141629. The reversal of 21141621 is 12614112.

21141621 is a `hidden beast` number, since 2 + 1 + 1 + 41 + 621 = 666.

It is not a de Polignac number, because 21141621 - 2¹³ = 21133429 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21141594 and 21141603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21141629) 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, 391485 + ... + 391538.

It is an arithmetic number, because the mean of its divisors is an integer number (3915120).

Almost surely, 2^21141621 is an apocalyptic number.

It is an amenable number.

21141621 is a deficient number, since it is larger than the sum of its proper divisors (10179339).

21141621 is an equidigital number, since it uses as much as digits as its factorization.

21141621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 783032 (or 783026 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

The square root of 21141621 is about 4598.0018486295. The cubic root of 21141621 is about 276.5112216908.

Adding to 21141621 its reverse (12614112), we get a palindrome (33755733).

The spelling of 21141621 in words is "twenty-one million, one hundred forty-one thousand, six hundred twenty-one".