21235133220 has 48 divisors (see below), whose sum is σ = 67952427648. Its totient is φ = 4853744640.

The previous prime is 21235133209. The next prime is 21235133237. The reversal of 21235133220 is 2233153212.

It is a happy number.

It is a super-2 number, since 2×21235133220² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25279501 + ... + 25280340.

It is an arithmetic number, because the mean of its divisors is an integer number (1415675576).

Almost surely, 2^21235133220 is an apocalyptic number.

21235133220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21235133220 is an abundant number, since it is smaller than the sum of its proper divisors (46717294428).

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

21235133220 is a wasteful number, since it uses less digits than its factorization.

21235133220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50559860 (or 50559858 counting only the distinct ones).

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

Adding to 21235133220 its reverse (2233153212), we get a palindrome (23468286432).

The spelling of 21235133220 in words is "twenty-one billion, two hundred thirty-five million, one hundred thirty-three thousand, two hundred twenty".