21915011871 has 12 divisors (see below), whose sum is σ = 31656364272. Its totient is φ = 14609386176.

The previous prime is 21915011779. The next prime is 21915011887. The reversal of 21915011871 is 17811051912.

It is not a de Polignac number, because 21915011871 - 2⁹ = 21915011359 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21915091871) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 290350 + ... + 357956.

It is an arithmetic number, because the mean of its divisors is an integer number (2638030356).

Almost surely, 2^21915011871 is an apocalyptic number.

21915011871 is a deficient number, since it is larger than the sum of its proper divisors (9741352401).

21915011871 is a wasteful number, since it uses less digits than its factorization.

21915011871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103630 (or 103627 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 36.

The spelling of 21915011871 in words is "twenty-one billion, nine hundred fifteen million, eleven thousand, eight hundred seventy-one".