221402979 has 24 divisors (see below), whose sum is σ = 366163200. Its totient is φ = 126283248.

The previous prime is 221402971. The next prime is 221402999. The reversal of 221402979 is 979204122.

It is not a de Polignac number, because 221402979 - 2³ = 221402971 is a prime.

It is a super-2 number, since 2×221402979² = 98038558220148882, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221402971) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34804 + ... + 40670.

It is an arithmetic number, because the mean of its divisors is an integer number (15256800).

Almost surely, 2^221402979 is an apocalyptic number.

221402979 is a deficient number, since it is larger than the sum of its proper divisors (144760221).

221402979 is a wasteful number, since it uses less digits than its factorization.

221402979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6479 (or 6476 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 221402979 is about 14879.6162248897. The cubic root of 221402979 is about 604.9616158513.

The spelling of 221402979 in words is "two hundred twenty-one million, four hundred two thousand, nine hundred seventy-nine".