21002515071 has 16 divisors (see below), whose sum is σ = 29663772768. Its totient is φ = 13172198400.

The previous prime is 21002515043. The next prime is 21002515087. The reversal of 21002515071 is 17051520012.

It is not a de Polignac number, because 21002515071 - 2²⁶ = 20935406207 is a prime.

It is a super-2 number, since 2×21002515071² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002519071) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26061 + ... + 206601.

It is an arithmetic number, because the mean of its divisors is an integer number (1853985798).

Almost surely, 2^21002515071 is an apocalyptic number.

21002515071 is a deficient number, since it is larger than the sum of its proper divisors (8661257697).

21002515071 is a wasteful number, since it uses less digits than its factorization.

21002515071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182842.

The product of its (nonzero) digits is 700, while the sum is 24.

The spelling of 21002515071 in words is "twenty-one billion, two million, five hundred fifteen thousand, seventy-one".