221435491 has 8 divisors (see below), whose sum is σ = 227905760. Its totient is φ = 214990848.

The previous prime is 221435441. The next prime is 221435497. The reversal of 221435491 is 194534122.

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

It is a 15-Lehmer number, since φ(221435491) divides (221435491-1)¹⁵.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221435491 is a prime.

It is a super-2 number, since 2×221435491² = 98067353348822162, which contains 22 as substring.

It is a pancake number, because a pancake can be divided into 221435491 parts by 21044 straight cuts.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221435497) 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, 11875 + ... + 24163.

It is an arithmetic number, because the mean of its divisors is an integer number (28488220).

Almost surely, 2^221435491 is an apocalyptic number.

221435491 is a deficient number, since it is larger than the sum of its proper divisors (6470269).

221435491 is a wasteful number, since it uses less digits than its factorization.

221435491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12813.

The product of its digits is 8640, while the sum is 31.

The square root of 221435491 is about 14880.7086860808. The cubic root of 221435491 is about 604.9912263373.

The spelling of 221435491 in words is "two hundred twenty-one million, four hundred thirty-five thousand, four hundred ninety-one".