21015130535 has 48 divisors (see below), whose sum is σ = 29628680256. Its totient is φ = 14267054592.

The previous prime is 21015130531. The next prime is 21015130553. The reversal of 21015130535 is 53503151012.

It is a happy number.

It is not a de Polignac number, because 21015130535 - 2² = 21015130531 is a prime.

It is a super-2 number, since 2×21015130535² (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 (21015130531) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11987219 + ... + 11988971.

It is an arithmetic number, because the mean of its divisors is an integer number (617264172).

Almost surely, 2^21015130535 is an apocalyptic number.

21015130535 is a deficient number, since it is larger than the sum of its proper divisors (8613549721).

21015130535 is a wasteful number, since it uses less digits than its factorization.

21015130535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2232 (or 2225 counting only the distinct ones).

The product of its (nonzero) digits is 2250, while the sum is 26.

Adding to 21015130535 its reverse (53503151012), we get a palindrome (74518281547).

The spelling of 21015130535 in words is "twenty-one billion, fifteen million, one hundred thirty thousand, five hundred thirty-five".