221407887 has 4 divisors (see below), whose sum is σ = 295210520. Its totient is φ = 147605256.

The previous prime is 221407883. The next prime is 221407909. The reversal of 221407887 is 788704122.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 221407887 - 2² = 221407883 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221407883) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36901312 + ... + 36901317.

It is an arithmetic number, because the mean of its divisors is an integer number (73802630).

Almost surely, 2^221407887 is an apocalyptic number.

221407887 is a deficient number, since it is larger than the sum of its proper divisors (73802633).

221407887 is an equidigital number, since it uses as much as digits as its factorization.

221407887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73802632.

The product of its (nonzero) digits is 50176, while the sum is 39.

The square root of 221407887 is about 14879.7811475841. The cubic root of 221407887 is about 604.9660860255.

The spelling of 221407887 in words is "two hundred twenty-one million, four hundred seven thousand, eight hundred eighty-seven".