21230515 has 8 divisors (see below), whose sum is σ = 25671888. Its totient is φ = 16854240.

The previous prime is 21230509. The next prime is 21230533. The reversal of 21230515 is 51503212.

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

It is not a de Polignac number, because 21230515 - 2⁵ = 21230483 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21230492 and 21230501.

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, 15552 + ... + 16861.

It is an arithmetic number, because the mean of its divisors is an integer number (3208986).

Almost surely, 2^21230515 is an apocalyptic number.

21230515 is a deficient number, since it is larger than the sum of its proper divisors (4441373).

21230515 is a wasteful number, since it uses less digits than its factorization.

21230515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32549.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 21230515 is about 4607.6582989627. The cubic root of 21230515 is about 276.8982279361.

Adding to 21230515 its reverse (51503212), we get a palindrome (72733727).

The spelling of 21230515 in words is "twenty-one million, two hundred thirty thousand, five hundred fifteen".