221979969 has 12 divisors (see below), whose sum is σ = 334578816. Its totient is φ = 141552312.

The previous prime is 221979959. The next prime is 221979971. The reversal of 221979969 is 969979122.

It is not a de Polignac number, because 221979969 - 2⁷ = 221979841 is a prime.

It is a super-2 number, since 2×221979969² = 98550213274481922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221979959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 535977 + ... + 536390.

It is an arithmetic number, because the mean of its divisors is an integer number (27881568).

Almost surely, 2^221979969 is an apocalyptic number.

It is an amenable number.

221979969 is a deficient number, since it is larger than the sum of its proper divisors (112598847).

221979969 is a wasteful number, since it uses less digits than its factorization.

221979969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1072396 (or 1072393 counting only the distinct ones).

The product of its digits is 1102248, while the sum is 54.

The square root of 221979969 is about 14898.9922142405. The cubic root of 221979969 is about 605.4866825890.

The spelling of 221979969 in words is "two hundred twenty-one million, nine hundred seventy-nine thousand, nine hundred sixty-nine".