221187969 has 32 divisors (see below), whose sum is σ = 354378240. Its totient is φ = 135818496.

The previous prime is 221187937. The next prime is 221187983. The reversal of 221187969 is 969781122.

221187969 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221187969 - 2⁵ = 221187937 is a prime.

It is a super-2 number, since 2×221187969² = 97848235260689922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221187929) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16447 + ... + 26699.

It is an arithmetic number, because the mean of its divisors is an integer number (11074320).

Almost surely, 2^221187969 is an apocalyptic number.

It is an amenable number.

221187969 is a deficient number, since it is larger than the sum of its proper divisors (133190271).

221187969 is a wasteful number, since it uses less digits than its factorization.

221187969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10326 (or 10320 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The square root of 221187969 is about 14872.3894852172. The cubic root of 221187969 is about 604.7657212794.

The spelling of 221187969 in words is "two hundred twenty-one million, one hundred eighty-seven thousand, nine hundred sixty-nine".