3121123921 has 2 divisors, whose sum is σ = 3121123922. Its totient is φ = 3121123920.

The previous prime is 3121123909. The next prime is 3121123963. The reversal of 3121123921 is 1293211213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1743897600 + 1377226321 = 41760^2 + 37111^2 .

It is a cyclic number.

It is not a de Polignac number, because 3121123921 - 2⁷ = 3121123793 is a prime.

It is not a weakly prime, because it can be changed into another prime (3121124921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1560561960 + 1560561961.

It is an arithmetic number, because the mean of its divisors is an integer number (1560561961).

Almost surely, 2^3121123921 is an apocalyptic number.

It is an amenable number.

3121123921 is a deficient number, since it is larger than the sum of its proper divisors (1).

3121123921 is an equidigital number, since it uses as much as digits as its factorization.

3121123921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 648, while the sum is 25.

The square root of 3121123921 is about 55867.0199760109. The cubic root of 3121123921 is about 1461.4041537522.

The spelling of 3121123921 in words is "three billion, one hundred twenty-one million, one hundred twenty-three thousand, nine hundred twenty-one".