3121320405 has 32 divisors (see below), whose sum is σ = 5891678208. Its totient is φ = 1380859200.

The previous prime is 3121320379. The next prime is 3121320413. The reversal of 3121320405 is 5040231213.

3121320405 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 3121320405 - 2⁶ = 3121320341 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 476211 + ... + 482720.

It is an arithmetic number, because the mean of its divisors is an integer number (184114944).

Almost surely, 2^3121320405 is an apocalyptic number.

3121320405 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

3121320405 is a deficient number, since it is larger than the sum of its proper divisors (2770357803).

3121320405 is a wasteful number, since it uses less digits than its factorization.

3121320405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 958977.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 3121320405 is about 55868.7784455683. The cubic root of 3121320405 is about 1461.4348196827.

Adding to 3121320405 its reverse (5040231213), we get a palindrome (8161551618).

The spelling of 3121320405 in words is "three billion, one hundred twenty-one million, three hundred twenty thousand, four hundred five".