221501952 has 300 divisors, whose sum is σ = 776119410. Its totient is φ = 62705664.

The previous prime is 221501941. The next prime is 221501957. The reversal of 221501952 is 259105122.

It can be written as a sum of positive squares in only one way, i.e., 171714816 + 49787136 = 13104^2 + 7056^2 .

It is a super-3 number, since 3×221501952³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (221501957) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 2032074 + ... + 2032182.

Almost surely, 2^221501952 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221501952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (388059705).

221501952 is an abundant number, since it is smaller than the sum of its proper divisors (554617458).

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

221501952 is an equidigital number, since it uses as much as digits as its factorization.

221501952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153 (or 121 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 221501952 is about 14882.9416447153. The cubic root of 221501952 is about 605.0517470480.

The spelling of 221501952 in words is "two hundred twenty-one million, five hundred one thousand, nine hundred fifty-two".