21515002 has 8 divisors (see below), whose sum is σ = 32959296. Its totient is φ = 10528572.

The previous prime is 21514993. The next prime is 21515003. The reversal of 21515002 is 20051512.

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

It is a super-2 number, since 2×21515002² = 925790622120008, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21515003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114348 + ... + 114535.

It is an arithmetic number, because the mean of its divisors is an integer number (4119912).

Almost surely, 2^21515002 is an apocalyptic number.

21515002 is a deficient number, since it is larger than the sum of its proper divisors (11444294).

21515002 is a wasteful number, since it uses less digits than its factorization.

21515002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228932.

The product of its (nonzero) digits is 100, while the sum is 16.

The square root of 21515002 is about 4638.4266729140. The cubic root of 21515002 is about 278.1295481645.

Adding to 21515002 its reverse (20051512), we get a palindrome (41566514).

The spelling of 21515002 in words is "twenty-one million, five hundred fifteen thousand, two".