21442013 has 4 divisors (see below), whose sum is σ = 22570560. Its totient is φ = 20313468.

The previous prime is 21442009. The next prime is 21442019. The reversal of 21442013 is 31024412.

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 21442013 - 2² = 21442009 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 21441982 and 21442000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21442019) 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, 564245 + ... + 564282.

It is an arithmetic number, because the mean of its divisors is an integer number (5642640).

Almost surely, 2^21442013 is an apocalyptic number.

It is an amenable number.

21442013 is a deficient number, since it is larger than the sum of its proper divisors (1128547).

21442013 is a wasteful number, since it uses less digits than its factorization.

21442013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1128546.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21442013 is about 4630.5521269067. The cubic root of 21442013 is about 277.8146764435.

Adding to 21442013 its reverse (31024412), we get a palindrome (52466425).

The spelling of 21442013 in words is "twenty-one million, four hundred forty-two thousand, thirteen".