221401332 has 18 divisors (see below), whose sum is σ = 559653458. Its totient is φ = 73800432.

The previous prime is 221401331. The next prime is 221401333. The reversal of 221401332 is 233104122.

It is an interprime number because it is at equal distance from previous prime (221401331) and next prime (221401333).

It can be written as a sum of positive squares in only one way, i.e., 208398096 + 13003236 = 14436^2 + 3606^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×221401332² = 98037099622748448, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221401331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3074983 + ... + 3075054.

Almost surely, 2^221401332 is an apocalyptic number.

It is an amenable number.

221401332 is an abundant number, since it is smaller than the sum of its proper divisors (338252126).

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

221401332 is a wasteful number, since it uses less digits than its factorization.

221401332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6150047 (or 6150042 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 221401332 is about 14879.5608806174. The cubic root of 221401332 is about 604.9601157597.

Adding to 221401332 its reverse (233104122), we get a palindrome (454505454).

The spelling of 221401332 in words is "two hundred twenty-one million, four hundred one thousand, three hundred thirty-two".