221542380 has 36 divisors (see below), whose sum is σ = 672012432. Its totient is φ = 59077920.

The previous prime is 221542369. The next prime is 221542381. The reversal of 221542380 is 83245122.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×221542380² = 98162052272128800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221542381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 615216 + ... + 615575.

It is an arithmetic number, because the mean of its divisors is an integer number (18667012).

Almost surely, 2^221542380 is an apocalyptic number.

221542380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221542380 is an abundant number, since it is smaller than the sum of its proper divisors (450470052).

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

221542380 is a wasteful number, since it uses less digits than its factorization.

221542380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1230806 (or 1230801 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 221542380 is about 14884.2997819850. The cubic root of 221542380 is about 605.0885556687.

The spelling of 221542380 in words is "two hundred twenty-one million, five hundred forty-two thousand, three hundred eighty".