981645221 has 8 divisors (see below), whose sum is σ = 1024700544. Its totient is φ = 938621200.

The previous prime is 981645209. The next prime is 981645251. The reversal of 981645221 is 122546189.

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 981645221 - 2¹⁰ = 981644197 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (981645251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75071 + ... + 87171.

It is an arithmetic number, because the mean of its divisors is an integer number (128087568).

Almost surely, 2^981645221 is an apocalyptic number.

It is an amenable number.

981645221 is a deficient number, since it is larger than the sum of its proper divisors (43055323).

981645221 is a wasteful number, since it uses less digits than its factorization.

981645221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15651.

The product of its digits is 34560, while the sum is 38.

The square root of 981645221 is about 31331.2179941987. The cubic root of 981645221 is about 993.8439207884.

The spelling of 981645221 in words is "nine hundred eighty-one million, six hundred forty-five thousand, two hundred twenty-one".