21271105015 has 4 divisors (see below), whose sum is σ = 25525326024. Its totient is φ = 17016884008.

The previous prime is 21271105003. The next prime is 21271105027. The reversal of 21271105015 is 51050117212.

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

It is an interprime number because it is at equal distance from previous prime (21271105003) and next prime (21271105027).

It is a cyclic number.

It is not a de Polignac number, because 21271105015 - 2⁷ = 21271104887 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, 2127110497 + ... + 2127110506.

It is an arithmetic number, because the mean of its divisors is an integer number (6381331506).

Almost surely, 2^21271105015 is an apocalyptic number.

21271105015 is a deficient number, since it is larger than the sum of its proper divisors (4254221009).

21271105015 is an equidigital number, since it uses as much as digits as its factorization.

21271105015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4254221008.

The product of its (nonzero) digits is 700, while the sum is 25.

The spelling of 21271105015 in words is "twenty-one billion, two hundred seventy-one million, one hundred five thousand, fifteen".