1211000013405 has 192 divisors, whose sum is σ = 2606718965760. Its totient is φ = 506434457088.

The previous prime is 1211000013403. The next prime is 1211000013427. The reversal of 1211000013405 is 5043100001121.

It is not a de Polignac number, because 1211000013405 - 2¹ = 1211000013403 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211000013403) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 252974422 + ... + 252979208.

It is an arithmetic number, because the mean of its divisors is an integer number (13576661280).

Almost surely, 2^{1211000013405} is an apocalyptic number.

1211000013405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1211000013405 is an abundant number, since it is smaller than the sum of its proper divisors (1395718952355).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1211000013405 is a wasteful number, since it uses less digits than its factorization.

1211000013405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5360 (or 5357 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

Adding to 1211000013405 its reverse (5043100001121), we get a palindrome (6254100014526).

The spelling of 1211000013405 in words is "one trillion, two hundred eleven billion, thirteen thousand, four hundred five".