21253213030506 has 16 divisors (see below), whose sum is σ = 42517018291104. Its totient is φ = 7082638971824.

The previous prime is 21253213030501. The next prime is 21253213030507. The reversal of 21253213030506 is 60503031235212.

It is not an unprimeable number, because it can be changed into a prime (21253213030501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 441316836 + ... + 441364991.

It is an arithmetic number, because the mean of its divisors is an integer number (2657313643194).

Almost surely, 2^{21253213030506} is an apocalyptic number.

21253213030506 is an abundant number, since it is smaller than the sum of its proper divisors (21263805260598).

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

21253213030506 is a wasteful number, since it uses less digits than its factorization.

21253213030506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 882685845.

The product of its (nonzero) digits is 32400, while the sum is 33.

Adding to 21253213030506 its reverse (60503031235212), we get a palindrome (81756244265718).

The spelling of 21253213030506 in words is "twenty-one trillion, two hundred fifty-three billion, two hundred thirteen million, thirty thousand, five hundred six".