2086781657 has 2 divisors, whose sum is σ = 2086781658. Its totient is φ = 2086781656.

The previous prime is 2086781639. The next prime is 2086781677. The reversal of 2086781657 is 7561876802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1583721616 + 503060041 = 39796^2 + 22429^2 .

It is a cyclic number.

It is not a de Polignac number, because 2086781657 - 2⁸ = 2086781401 is a prime.

It is not a weakly prime, because it can be changed into another prime (2086781617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1043390828 + 1043390829.

It is an arithmetic number, because the mean of its divisors is an integer number (1043390829).

Almost surely, 2^2086781657 is an apocalyptic number.

It is an amenable number.

2086781657 is a deficient number, since it is larger than the sum of its proper divisors (1).

2086781657 is an equidigital number, since it uses as much as digits as its factorization.

2086781657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1128960, while the sum is 50.

The square root of 2086781657 is about 45681.3053338015. The cubic root of 2086781657 is about 1277.8866610157.

The spelling of 2086781657 in words is "two billion, eighty-six million, seven hundred eighty-one thousand, six hundred fifty-seven".