221291493 has 8 divisors (see below), whose sum is σ = 295757856. Its totient is φ = 147176400.

The previous prime is 221291491. The next prime is 221291503. The reversal of 221291493 is 394192122.

221291493 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 221291493 - 2¹ = 221291491 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221291491) 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, 86343 + ... + 88868.

It is an arithmetic number, because the mean of its divisors is an integer number (36969732).

Almost surely, 2^221291493 is an apocalyptic number.

It is an amenable number.

221291493 is a deficient number, since it is larger than the sum of its proper divisors (74466363).

221291493 is a wasteful number, since it uses less digits than its factorization.

221291493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175635.

The product of its digits is 7776, while the sum is 33.

The square root of 221291493 is about 14875.8694871930. The cubic root of 221291493 is about 604.8600573348.

The spelling of 221291493 in words is "two hundred twenty-one million, two hundred ninety-one thousand, four hundred ninety-three".