21012455215 has 8 divisors (see below), whose sum is σ = 25896431520. Its totient is φ = 16355640672.

The previous prime is 21012455201. The next prime is 21012455227. The reversal of 21012455215 is 51255421012.

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

It is a cyclic number.

It is not a de Polignac number, because 21012455215 - 2¹¹ = 21012453167 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56790235 + ... + 56790604.

It is an arithmetic number, because the mean of its divisors is an integer number (3237053940).

Almost surely, 2^21012455215 is an apocalyptic number.

21012455215 is a deficient number, since it is larger than the sum of its proper divisors (4883976305).

21012455215 is a wasteful number, since it uses less digits than its factorization.

21012455215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113580881.

The product of its (nonzero) digits is 4000, while the sum is 28.

Adding to 21012455215 its reverse (51255421012), we get a palindrome (72267876227).

The spelling of 21012455215 in words is "twenty-one billion, twelve million, four hundred fifty-five thousand, two hundred fifteen".