221402987 has 8 divisors (see below), whose sum is σ = 242476080. Its totient is φ = 200907360.

The previous prime is 221402971. The next prime is 221402999. The reversal of 221402987 is 789204122.

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

It is a cyclic number.

It is not a de Polignac number, because 221402987 - 2⁴ = 221402971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221402287) 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, 143564 + ... + 145097.

It is an arithmetic number, because the mean of its divisors is an integer number (30309510).

Almost surely, 2^221402987 is an apocalyptic number.

221402987 is a deficient number, since it is larger than the sum of its proper divisors (21073093).

221402987 is a wasteful number, since it uses less digits than its factorization.

221402987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288733.

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 221402987 is about 14879.6164937138. The cubic root of 221402987 is about 604.9616231377.

The spelling of 221402987 in words is "two hundred twenty-one million, four hundred two thousand, nine hundred eighty-seven".