221297661544961 has 8 divisors (see below), whose sum is σ = 226695368659200. Its totient is φ = 215899964105760.

The previous prime is 221297661544937. The next prime is 221297661545003. The reversal of 221297661544961 is 169445166792122.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221297661544961 is a prime.

It is a super-2 number, since 2×221297661544961² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (221297661504961) 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, 70033580 + ... + 73125218.

It is an arithmetic number, because the mean of its divisors is an integer number (28336921082400).

Almost surely, 2^{221297661544961} is an apocalyptic number.

It is an amenable number.

221297661544961 is a deficient number, since it is larger than the sum of its proper divisors (5397707114239).

221297661544961 is a wasteful number, since it uses less digits than its factorization.

221297661544961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4837519.

The product of its digits is 78382080, while the sum is 65.

The spelling of 221297661544961 in words is "two hundred twenty-one trillion, two hundred ninety-seven billion, six hundred sixty-one million, five hundred forty-four thousand, nine hundred sixty-one".