21513146 has 8 divisors (see below), whose sum is σ = 32314944. Its totient is φ = 10741500.

The previous prime is 21513127. The next prime is 21513161. The reversal of 21513146 is 64131512.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5660 + ... + 8663.

It is an arithmetic number, because the mean of its divisors is an integer number (4039368).

Almost surely, 2^21513146 is an apocalyptic number.

21513146 is a deficient number, since it is larger than the sum of its proper divisors (10801798).

21513146 is a wasteful number, since it uses less digits than its factorization.

21513146 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15076.

The product of its digits is 720, while the sum is 23.

The square root of 21513146 is about 4638.2266007603. The cubic root of 21513146 is about 278.1215502833.

Adding to 21513146 its reverse (64131512), we get a palindrome (85644658).

The spelling of 21513146 in words is "twenty-one million, five hundred thirteen thousand, one hundred forty-six".