221680969 has 16 divisors (see below), whose sum is σ = 252840960. Its totient is φ = 193121280.

The previous prime is 221680967. The next prime is 221680993. The reversal of 221680969 is 969086122.

221680969 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 221680969 - 2¹ = 221680967 is a prime.

It is a super-2 number, since 2×221680969² = 98284904033557922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221680967) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2977 + ... + 21265.

It is an arithmetic number, because the mean of its divisors is an integer number (15802560).

Almost surely, 2^221680969 is an apocalyptic number.

It is an amenable number.

221680969 is a deficient number, since it is larger than the sum of its proper divisors (31159991).

221680969 is a wasteful number, since it uses less digits than its factorization.

221680969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18360.

The product of its (nonzero) digits is 93312, while the sum is 43.

The square root of 221680969 is about 14888.9545972845. The cubic root of 221680969 is about 605.2147032973.

The spelling of 221680969 in words is "two hundred twenty-one million, six hundred eighty thousand, nine hundred sixty-nine".