21413015 has 8 divisors (see below), whose sum is σ = 27672288. Its totient is φ = 15812640.

The previous prime is 21413009. The next prime is 21413027. The reversal of 21413015 is 51031412.

21413015 = 11² + 12² + ... + 400².

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

It is a de Polignac number, because none of the positive numbers 2^k-21413015 is a prime.

It is a super-2 number, since 2×21413015² = 917034422780450, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21412984 and 21413002.

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, 164651 + ... + 164780.

It is an arithmetic number, because the mean of its divisors is an integer number (3459036).

Almost surely, 2^21413015 is an apocalyptic number.

21413015 is a deficient number, since it is larger than the sum of its proper divisors (6259273).

21413015 is a wasteful number, since it uses less digits than its factorization.

21413015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329449.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 21413015 is about 4627.4199074646. The cubic root of 21413015 is about 277.6893818584.

Adding to 21413015 its reverse (51031412), we get a palindrome (72444427).

The spelling of 21413015 in words is "twenty-one million, four hundred thirteen thousand, fifteen".