221908377601 has 4 divisors (see below), whose sum is σ = 224196092932. Its totient is φ = 219620662272.

The previous prime is 221908377599. The next prime is 221908377631. The reversal of 221908377601 is 106773809122.

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 74625126976 + 147283250625 = 273176^2 + 383775^2 .

It is a cyclic number.

It is not a de Polignac number, because 221908377601 - 2¹ = 221908377599 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221908377631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1143857520 + ... + 1143857713.

It is an arithmetic number, because the mean of its divisors is an integer number (56049023233).

Almost surely, 2^221908377601 is an apocalyptic number.

It is an amenable number.

221908377601 is a deficient number, since it is larger than the sum of its proper divisors (2287715331).

221908377601 is an equidigital number, since it uses as much as digits as its factorization.

221908377601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2287715330.

The product of its (nonzero) digits is 254016, while the sum is 46.

The spelling of 221908377601 in words is "two hundred twenty-one billion, nine hundred eight million, three hundred seventy-seven thousand, six hundred one".