21312514 has 4 divisors (see below), whose sum is σ = 31968774. Its totient is φ = 10656256.

The previous prime is 21312493. The next prime is 21312517. The reversal of 21312514 is 41521312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 18190225 + 3122289 = 4265^2 + 1767^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21312491 and 21312500.

It is not an unprimeable number, because it can be changed into a prime (21312517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5328127 + ... + 5328130.

Almost surely, 2^21312514 is an apocalyptic number.

21312514 is a deficient number, since it is larger than the sum of its proper divisors (10656260).

21312514 is a wasteful number, since it uses less digits than its factorization.

21312514 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10656259.

The product of its digits is 240, while the sum is 19.

The square root of 21312514 is about 4616.5478444396. The cubic root of 21312514 is about 277.2542596285.

Adding to 21312514 its reverse (41521312), we get a palindrome (62833826).

The spelling of 21312514 in words is "twenty-one million, three hundred twelve thousand, five hundred fourteen".