1355121405 has 48 divisors (see below), whose sum is σ = 2604476160. Its totient is φ = 646243200.

The previous prime is 1355121379. The next prime is 1355121409. The reversal of 1355121405 is 5041215531.

1355121405 is a `hidden beast` number, since 1 + 3 + 5 + 512 + 140 + 5 = 666.

It is not a de Polignac number, because 1355121405 - 2⁷ = 1355121277 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1355121409) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7756 + ... + 52634.

It is an arithmetic number, because the mean of its divisors is an integer number (54259920).

Almost surely, 2^1355121405 is an apocalyptic number.

1355121405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1355121405 is a deficient number, since it is larger than the sum of its proper divisors (1249354755).

1355121405 is a wasteful number, since it uses less digits than its factorization.

1355121405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44962 (or 44959 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

The square root of 1355121405 is about 36811.9736634699. The cubic root of 1355121405 is about 1106.6052724667.

Adding to 1355121405 its reverse (5041215531), we get a palindrome (6396336936).

It can be divided in two parts, 1355 and 121405, that added together give a triangular number (122760 = T₄₉₅).

The spelling of 1355121405 in words is "one billion, three hundred fifty-five million, one hundred twenty-one thousand, four hundred five".