21615014 has 4 divisors (see below), whose sum is σ = 32422524. Its totient is φ = 10807506.

The previous prime is 21615001. The next prime is 21615047. The reversal of 21615014 is 41051612.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5403752 + ... + 5403755.

It is an arithmetic number, because the mean of its divisors is an integer number (8105631).

Almost surely, 2^21615014 is an apocalyptic number.

21615014 is a deficient number, since it is larger than the sum of its proper divisors (10807510).

21615014 is a wasteful number, since it uses less digits than its factorization.

21615014 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10807509.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 21615014 is about 4649.1949840806. The cubic root of 21615014 is about 278.5598417522.

Adding to 21615014 its reverse (41051612), we get a palindrome (62666626).

The spelling of 21615014 in words is "twenty-one million, six hundred fifteen thousand, fourteen".