2681956421 has 2 divisors, whose sum is σ = 2681956422. Its totient is φ = 2681956420.

The previous prime is 2681956399. The next prime is 2681956427. The reversal of 2681956421 is 1246591862.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1984257025 + 697699396 = 44545^2 + 26414^2 .

It is a cyclic number.

It is not a de Polignac number, because 2681956421 - 2⁶ = 2681956357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2681956427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1340978210 + 1340978211.

It is an arithmetic number, because the mean of its divisors is an integer number (1340978211).

Almost surely, 2^2681956421 is an apocalyptic number.

It is an amenable number.

2681956421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2681956421 is an equidigital number, since it uses as much as digits as its factorization.

2681956421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 207360, while the sum is 44.

The square root of 2681956421 is about 51787.6087592389. The cubic root of 2681956421 is about 1389.3678302986.

The spelling of 2681956421 in words is "two billion, six hundred eighty-one million, nine hundred fifty-six thousand, four hundred twenty-one".