21235771071 has 6 divisors (see below), whose sum is σ = 30673891560. Its totient is φ = 14157180708.

The previous prime is 21235771061. The next prime is 21235771087. The reversal of 21235771071 is 17017753212.

It is a happy number.

21235771071 is a `hidden beast` number, since 2 + 1 + 2 + 3 + 577 + 10 + 71 = 666.

It is not a de Polignac number, because 21235771071 - 2⁹ = 21235770559 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21235771061) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1179765051 + ... + 1179765068.

It is an arithmetic number, because the mean of its divisors is an integer number (5112315260).

Almost surely, 2^21235771071 is an apocalyptic number.

21235771071 is a deficient number, since it is larger than the sum of its proper divisors (9438120489).

21235771071 is a wasteful number, since it uses less digits than its factorization.

21235771071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2359530125 (or 2359530122 counting only the distinct ones).

The product of its (nonzero) digits is 20580, while the sum is 36.

The spelling of 21235771071 in words is "twenty-one billion, two hundred thirty-five million, seven hundred seventy-one thousand, seventy-one".