2151938777 has 2 divisors, whose sum is σ = 2151938778. Its totient is φ = 2151938776.

The previous prime is 2151938731. The next prime is 2151938779. The reversal of 2151938777 is 7778391512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1607929801 + 544008976 = 40099^2 + 23324^2 .

It is a cyclic number.

It is not a de Polignac number, because 2151938777 - 2¹⁸ = 2151676633 is a prime.

Together with 2151938779, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2151938779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1075969388 + 1075969389.

It is an arithmetic number, because the mean of its divisors is an integer number (1075969389).

Almost surely, 2^2151938777 is an apocalyptic number.

It is an amenable number.

2151938777 is a deficient number, since it is larger than the sum of its proper divisors (1).

2151938777 is an equidigital number, since it uses as much as digits as its factorization.

2151938777 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 740880, while the sum is 50.

The square root of 2151938777 is about 46388.9941365406. The cubic root of 2151938777 is about 1291.0507187712.

The spelling of 2151938777 in words is "two billion, one hundred fifty-one million, nine hundred thirty-eight thousand, seven hundred seventy-seven".