221136520 has 64 divisors (see below), whose sum is σ = 548985600. Its totient is φ = 79495680.

The previous prime is 221136479. The next prime is 221136523. The reversal of 221136520 is 25631122.

221136520 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 221136491 and 221136500.

It is not an unprimeable number, because it can be changed into a prime (221136523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36337 + ... + 41983.

It is an arithmetic number, because the mean of its divisors is an integer number (8577900).

Almost surely, 2^221136520 is an apocalyptic number.

221136520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221136520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (274492800).

221136520 is an abundant number, since it is smaller than the sum of its proper divisors (327849080).

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

221136520 is a wasteful number, since it uses less digits than its factorization.

221136520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5758 (or 5754 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 221136520 is about 14870.6597029184. The cubic root of 221136520 is about 604.7188275227.

Adding to 221136520 its reverse (25631122), we get a palindrome (246767642).

The spelling of 221136520 in words is "two hundred twenty-one million, one hundred thirty-six thousand, five hundred twenty".