21523030206 has 16 divisors (see below), whose sum is σ = 44917628544. Its totient is φ = 6862415384.

The previous prime is 21523030187. The next prime is 21523030231. The reversal of 21523030206 is 60203032512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77981856 + ... + 77982131.

It is an arithmetic number, because the mean of its divisors is an integer number (2807351784).

Almost surely, 2^21523030206 is an apocalyptic number.

21523030206 is an abundant number, since it is smaller than the sum of its proper divisors (23394598338).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21523030206 is a wasteful number, since it uses less digits than its factorization.

21523030206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155964015.

The product of its (nonzero) digits is 2160, while the sum is 24.

Adding to 21523030206 its reverse (60203032512), we get a palindrome (81726062718).

The spelling of 21523030206 in words is "twenty-one billion, five hundred twenty-three million, thirty thousand, two hundred six".