221972915 has 8 divisors (see below), whose sum is σ = 280386960. Its totient is φ = 168232032.

The previous prime is 221972897. The next prime is 221972921. The reversal of 221972915 is 519279122.

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 221972915 - 2¹⁴ = 221956531 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1168184 + ... + 1168373.

It is an arithmetic number, because the mean of its divisors is an integer number (35048370).

Almost surely, 2^221972915 is an apocalyptic number.

221972915 is a deficient number, since it is larger than the sum of its proper divisors (58414045).

221972915 is a wasteful number, since it uses less digits than its factorization.

221972915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2336581.

The product of its digits is 22680, while the sum is 38.

The square root of 221972915 is about 14898.7554849390. The cubic root of 221972915 is about 605.4802688747.

The spelling of 221972915 in words is "two hundred twenty-one million, nine hundred seventy-two thousand, nine hundred fifteen".