21230005 has 8 divisors (see below), whose sum is σ = 26097624. Its totient is φ = 16569600.

The previous prime is 21229979. The next prime is 21230017. The reversal of 21230005 is 50003212.

It can be written as a sum of positive squares in 4 ways, for example, as 998001 + 20232004 = 999^2 + 4498^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21230005 - 2⁷ = 21229877 is a prime.

It is a super-2 number, since 2×21230005² = 901426224600050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51576 + ... + 51985.

It is an arithmetic number, because the mean of its divisors is an integer number (3262203).

Almost surely, 2^21230005 is an apocalyptic number.

It is an amenable number.

21230005 is a deficient number, since it is larger than the sum of its proper divisors (4867619).

21230005 is a wasteful number, since it uses less digits than its factorization.

21230005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103607.

The product of its (nonzero) digits is 60, while the sum is 13.

The square root of 21230005 is about 4607.6029559848. The cubic root of 21230005 is about 276.8960106995.

Adding to 21230005 its reverse (50003212), we get a palindrome (71233217).

The spelling of 21230005 in words is "twenty-one million, two hundred thirty thousand, five".