3128756132421 has 24 divisors (see below), whose sum is σ = 4629702122136. Its totient is φ = 2034892776960.

The previous prime is 3128756132407. The next prime is 3128756132459. The reversal of 3128756132421 is 1242316578213.

3128756132421 is a `hidden beast` number, since 3 + 1 + 2 + 8 + 7 + 5 + 613 + 2 + 4 + 21 = 666.

3128756132421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 368127360225 + 2760628772196 = 606735^2 + 1661514^2 .

It is not a de Polignac number, because 3128756132421 - 2¹⁴ = 3128756116037 is a prime.

It is a super-2 number, since 2×3128756132421² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3128756132321) 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, 11829601 + ... + 12091193.

It is an arithmetic number, because the mean of its divisors is an integer number (192904255089).

Almost surely, 2^{3128756132421} is an apocalyptic number.

It is an amenable number.

3128756132421 is a deficient number, since it is larger than the sum of its proper divisors (1500945989715).

3128756132421 is a wasteful number, since it uses less digits than its factorization.

3128756132421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 294053 (or 294050 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The spelling of 3128756132421 in words is "three trillion, one hundred twenty-eight billion, seven hundred fifty-six million, one hundred thirty-two thousand, four hundred twenty-one".