13778381084221 has 8 divisors (see below), whose sum is σ = 14839925208920. Its totient is φ = 12717075339072.

The previous prime is 13778381084213. The next prime is 13778381084341. The reversal of 13778381084221 is 12248018387731.

It can be written as a sum of positive squares in 4 ways, for example, as 1155893765625 + 12622487318596 = 1075125^2 + 3552814^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 13778381084221 - 2³ = 13778381084213 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 (13778381084021) 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, 59474826 + ... + 59706043.

It is an arithmetic number, because the mean of its divisors is an integer number (1854990651115).

Almost surely, 2^{13778381084221} is an apocalyptic number.

It is an amenable number.

13778381084221 is a deficient number, since it is larger than the sum of its proper divisors (1061544124699).

13778381084221 is a wasteful number, since it uses less digits than its factorization.

13778381084221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119189775.

The product of its (nonzero) digits is 3612672, while the sum is 55.

The spelling of 13778381084221 in words is "thirteen trillion, seven hundred seventy-eight billion, three hundred eighty-one million, eighty-four thousand, two hundred twenty-one".