21044153215 has 4 divisors (see below), whose sum is σ = 25252983864. Its totient is φ = 16835322568.

The previous prime is 21044153197. The next prime is 21044153237. The reversal of 21044153215 is 51235144012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21044153215 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2104415317 + ... + 2104415326.

It is an arithmetic number, because the mean of its divisors is an integer number (6313245966).

Almost surely, 2^21044153215 is an apocalyptic number.

21044153215 is a deficient number, since it is larger than the sum of its proper divisors (4208830649).

21044153215 is an equidigital number, since it uses as much as digits as its factorization.

21044153215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4208830648.

The product of its (nonzero) digits is 4800, while the sum is 28.

Adding to 21044153215 its reverse (51235144012), we get a palindrome (72279297227).

The spelling of 21044153215 in words is "twenty-one billion, forty-four million, one hundred fifty-three thousand, two hundred fifteen".