221941581 has 8 divisors (see below), whose sum is σ = 301505760. Its totient is φ = 145169232.

The previous prime is 221941537. The next prime is 221941589. The reversal of 221941581 is 185149122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-221941581 is a prime.

It is a super-2 number, since 2×221941581² = 98516130753559122, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221941589) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 697771 + ... + 698088.

It is an arithmetic number, because the mean of its divisors is an integer number (37688220).

Almost surely, 2^221941581 is an apocalyptic number.

It is an amenable number.

221941581 is a deficient number, since it is larger than the sum of its proper divisors (79564179).

221941581 is a wasteful number, since it uses less digits than its factorization.

221941581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1395915.

The product of its digits is 5760, while the sum is 33.

The square root of 221941581 is about 14897.7038834849. The cubic root of 221941581 is about 605.4517773933.

The spelling of 221941581 in words is "two hundred twenty-one million, nine hundred forty-one thousand, five hundred eighty-one".