221680774657 has 4 divisors (see below), whose sum is σ = 221695434756. Its totient is φ = 221666114560.

The previous prime is 221680774643. The next prime is 221680774699. The reversal of 221680774657 is 756477086122.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 64921001616 + 156759773041 = 254796^2 + 395929^2 .

It is a cyclic number.

It is not a de Polignac number, because 221680774657 - 2³¹ = 219533291009 is a prime.

It is a super-2 number, since 2×221680774657² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221680774598 and 221680774607.

It is not an unprimeable number, because it can be changed into a prime (221680777657) 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 3 ways as a sum of consecutive naturals, for example, 7307344 + ... + 7337617.

It is an arithmetic number, because the mean of its divisors is an integer number (55423858689).

Almost surely, 2^221680774657 is an apocalyptic number.

It is an amenable number.

221680774657 is a deficient number, since it is larger than the sum of its proper divisors (14660099).

221680774657 is a wasteful number, since it uses less digits than its factorization.

221680774657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14660098.

The product of its (nonzero) digits is 7902720, while the sum is 55.

The spelling of 221680774657 in words is "two hundred twenty-one billion, six hundred eighty million, seven hundred seventy-four thousand, six hundred fifty-seven".