3123744778621 has 2 divisors, whose sum is σ = 3123744778622. Its totient is φ = 3123744778620.

The previous prime is 3123744778607. The next prime is 3123744778729. The reversal of 3123744778621 is 1268774473213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1969001110521 + 1154743668100 = 1403211^2 + 1074590^2 .

It is a cyclic number.

It is not a de Polignac number, because 3123744778621 - 2¹³ = 3123744770429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3123744778601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1561872389310 + 1561872389311.

It is an arithmetic number, because the mean of its divisors is an integer number (1561872389311).

Almost surely, 2^{3123744778621} is an apocalyptic number.

It is an amenable number.

3123744778621 is a deficient number, since it is larger than the sum of its proper divisors (1).

3123744778621 is an equidigital number, since it uses as much as digits as its factorization.

3123744778621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9483264, while the sum is 55.

The spelling of 3123744778621 in words is "three trillion, one hundred twenty-three billion, seven hundred forty-four million, seven hundred seventy-eight thousand, six hundred twenty-one".