21540025013 has 8 divisors (see below), whose sum is σ = 24417842400. Its totient is φ = 18836620848.

The previous prime is 21540025009. The next prime is 21540025019. The reversal of 21540025013 is 31052004512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21540025013 - 2² = 21540025009 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21540025013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21540025019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43603043 + ... + 43603536.

It is an arithmetic number, because the mean of its divisors is an integer number (3052230300).

Almost surely, 2^21540025013 is an apocalyptic number.

It is an amenable number.

21540025013 is a deficient number, since it is larger than the sum of its proper divisors (2877817387).

21540025013 is a wasteful number, since it uses less digits than its factorization.

21540025013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87206611.

The product of its (nonzero) digits is 1200, while the sum is 23.

Adding to 21540025013 its reverse (31052004512), we get a palindrome (52592029525).

The spelling of 21540025013 in words is "twenty-one billion, five hundred forty million, twenty-five thousand, thirteen".