1221402356271 has 24 divisors (see below), whose sum is σ = 1798753456656. Its totient is φ = 798471527040.

The previous prime is 1221402356263. The next prime is 1221402356297. The reversal of 1221402356271 is 1726532041221.

1221402356271 is a `hidden beast` number, since 1 + 2 + 2 + 1 + 4 + 0 + 23 + 5 + 627 + 1 = 666.

It is not a de Polignac number, because 1221402356271 - 2³ = 1221402356263 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221402396271) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5259345 + ... + 5486666.

It is an arithmetic number, because the mean of its divisors is an integer number (74948060694).

Almost surely, 2^{1221402356271} is an apocalyptic number.

1221402356271 is a deficient number, since it is larger than the sum of its proper divisors (577351100385).

1221402356271 is a wasteful number, since it uses less digits than its factorization.

1221402356271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10746263 (or 10746260 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

Adding to 1221402356271 its reverse (1726532041221), we get a palindrome (2947934397492).

The spelling of 1221402356271 in words is "one trillion, two hundred twenty-one billion, four hundred two million, three hundred fifty-six thousand, two hundred seventy-one".