221243251947 has 16 divisors (see below), whose sum is σ = 301682772480. Its totient is φ = 144186588000.

The previous prime is 221243251919. The next prime is 221243251961. The reversal of 221243251947 is 749152342122.

It is not a de Polignac number, because 221243251947 - 2¹⁰ = 221243250923 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221243251899 and 221243251908.

It is not an unprimeable number, because it can be changed into a prime (221243258947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4597429 + ... + 4645302.

It is an arithmetic number, because the mean of its divisors is an integer number (18855173280).

Almost surely, 2^221243251947 is an apocalyptic number.

221243251947 is a deficient number, since it is larger than the sum of its proper divisors (80439520533).

221243251947 is a wasteful number, since it uses less digits than its factorization.

221243251947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9242914.

The product of its digits is 241920, while the sum is 42.

The spelling of 221243251947 in words is "two hundred twenty-one billion, two hundred forty-three million, two hundred fifty-one thousand, nine hundred forty-seven".