1221311002131 has 96 divisors (see below), whose sum is σ = 2047897313280. Its totient is φ = 694343404800.

The previous prime is 1221311002129. The next prime is 1221311002139. The reversal of 1221311002131 is 1312001131221.

1221311002131 is a `hidden beast` number, since 1 + 221 + 311 + 0 + 0 + 2 + 131 = 666.

It is not a de Polignac number, because 1221311002131 - 2¹ = 1221311002129 is a prime.

It is a super-2 number, since 2×1221311002131² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221311002139) 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 95 ways as a sum of consecutive naturals, for example, 30525766 + ... + 30565748.

It is an arithmetic number, because the mean of its divisors is an integer number (21332263680).

Almost surely, 2^{1221311002131} is an apocalyptic number.

1221311002131 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1221311002131 is a deficient number, since it is larger than the sum of its proper divisors (826586311149).

1221311002131 is a wasteful number, since it uses less digits than its factorization.

1221311002131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40337 (or 40334 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

Adding to 1221311002131 its reverse (1312001131221), we get a palindrome (2533312133352).

The spelling of 1221311002131 in words is "one trillion, two hundred twenty-one billion, three hundred eleven million, two thousand, one hundred thirty-one".