20211153520 has 20 divisors (see below), whose sum is σ = 46990932120. Its totient is φ = 8084461376.

The previous prime is 20211153517. The next prime is 20211153527. The reversal of 20211153520 is 2535111202.

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 20211153491 and 20211153500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211153527) 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, 126319630 + ... + 126319789.

It is an arithmetic number, because the mean of its divisors is an integer number (2349546606).

Almost surely, 2^20211153520 is an apocalyptic number.

20211153520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20211153520 is an abundant number, since it is smaller than the sum of its proper divisors (26779778600).

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

20211153520 is a wasteful number, since it uses less digits than its factorization.

20211153520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252639432 (or 252639426 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 22.

Adding to 20211153520 its reverse (2535111202), we get a palindrome (22746264722).

The spelling of 20211153520 in words is "twenty billion, two hundred eleven million, one hundred fifty-three thousand, five hundred twenty".