21448861 has 4 divisors (see below), whose sum is σ = 24512992. Its totient is φ = 18384732.

The previous prime is 21448859. The next prime is 21448871. The reversal of 21448861 is 16884412.

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 a cyclic number.

It is not a de Polignac number, because 21448861 - 2¹ = 21448859 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21448831) 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, 1532055 + ... + 1532068.

It is an arithmetic number, because the mean of its divisors is an integer number (6128248).

Almost surely, 2^21448861 is an apocalyptic number.

It is an amenable number.

21448861 is a deficient number, since it is larger than the sum of its proper divisors (3064131).

21448861 is an equidigital number, since it uses as much as digits as its factorization.

21448861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3064130.

The product of its digits is 12288, while the sum is 34.

The square root of 21448861 is about 4631.2915045374. The cubic root of 21448861 is about 277.8442487977.

The spelling of 21448861 in words is "twenty-one million, four hundred forty-eight thousand, eight hundred sixty-one".