21205320526 has 8 divisors (see below), whose sum is σ = 34254748584. Its totient is φ = 9787071000.

The previous prime is 21205320509. The next prime is 21205320529. The reversal of 21205320526 is 62502350212.

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

It is a super-2 number, since 2×21205320526² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21205320494 and 21205320503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21205320529) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 407794600 + ... + 407794651.

It is an arithmetic number, because the mean of its divisors is an integer number (4281843573).

Almost surely, 2^21205320526 is an apocalyptic number.

21205320526 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21205320526 is a deficient number, since it is larger than the sum of its proper divisors (13049428058).

21205320526 is a wasteful number, since it uses less digits than its factorization.

21205320526 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 815589266.

The product of its (nonzero) digits is 7200, while the sum is 28.

Adding to 21205320526 its reverse (62502350212), we get a palindrome (83707670738).

The spelling of 21205320526 in words is "twenty-one billion, two hundred five million, three hundred twenty thousand, five hundred twenty-six".