221708086137649 has 4 divisors (see below), whose sum is σ = 221714764326400. Its totient is φ = 221701407948900.

The previous prime is 221708086137617. The next prime is 221708086137679. The reversal of 221708086137649 is 946731680807122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221708086137649 - 2⁵ = 221708086137617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221708086137679) 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, 3339044577 + ... + 3339110974.

It is an arithmetic number, because the mean of its divisors is an integer number (55428691081600).

Almost surely, 2^{221708086137649} is an apocalyptic number.

It is an amenable number.

221708086137649 is a deficient number, since it is larger than the sum of its proper divisors (6678188751).

221708086137649 is an equidigital number, since it uses as much as digits as its factorization.

221708086137649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6678188750.

The product of its (nonzero) digits is 48771072, while the sum is 64.

The spelling of 221708086137649 in words is "two hundred twenty-one trillion, seven hundred eight billion, eighty-six million, one hundred thirty-seven thousand, six hundred forty-nine".