221407345744391 has 4 divisors (see below), whose sum is σ = 222195272241984. Its totient is φ = 220619419246800.

The previous prime is 221407345744337. The next prime is 221407345744447. The reversal of 221407345744391 is 193447543704122.

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

It is a cyclic number.

It is not a de Polignac number, because 221407345744391 - 2⁶ = 221407345744327 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221407345734391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 393963248375 + ... + 393963248936.

It is an arithmetic number, because the mean of its divisors is an integer number (55548818060496).

Almost surely, 2^{221407345744391} is an apocalyptic number.

221407345744391 is a deficient number, since it is larger than the sum of its proper divisors (787926497593).

221407345744391 is an equidigital number, since it uses as much as digits as its factorization.

221407345744391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 787926497592.

The product of its (nonzero) digits is 20321280, while the sum is 56.

The spelling of 221407345744391 in words is "two hundred twenty-one trillion, four hundred seven billion, three hundred forty-five million, seven hundred forty-four thousand, three hundred ninety-one".