221861613601 has 8 divisors (see below), whose sum is σ = 243012721320. Its totient is φ = 201610553088.

The previous prime is 221861613583. The next prime is 221861613607. The reversal of 221861613601 is 106316168122.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 94126853601 + 127734760000 = 306801^2 + 357400^2 .

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 221861613601 - 2⁵ = 221861613569 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221861613607) 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, 225011286 + ... + 225012271.

It is an arithmetic number, because the mean of its divisors is an integer number (30376590165).

Almost surely, 2^221861613601 is an apocalyptic number.

It is an amenable number.

221861613601 is a deficient number, since it is larger than the sum of its proper divisors (21151107719).

221861613601 is a wasteful number, since it uses less digits than its factorization.

221861613601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450023603.

The product of its (nonzero) digits is 20736, while the sum is 37.

The spelling of 221861613601 in words is "two hundred twenty-one billion, eight hundred sixty-one million, six hundred thirteen thousand, six hundred one".