2657996747981 has 2 divisors, whose sum is σ = 2657996747982. Its totient is φ = 2657996747980.

The previous prime is 2657996747971. The next prime is 2657996748031. The reversal of 2657996747981 is 1897476997562.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2444313364900 + 213683383081 = 1563430^2 + 462259^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2657996747981 is a prime.

It is a super-2 number, since 2×2657996747981² (a number of 26 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2657996747896 and 2657996747905.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2657996747921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1328998373990 + 1328998373991.

It is an arithmetic number, because the mean of its divisors is an integer number (1328998373991).

Almost surely, 2^{2657996747981} is an apocalyptic number.

It is an amenable number.

2657996747981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2657996747981 is an equidigital number, since it uses as much as digits as its factorization.

2657996747981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2880541440, while the sum is 80.

The spelling of 2657996747981 in words is "two trillion, six hundred fifty-seven billion, nine hundred ninety-six million, seven hundred forty-seven thousand, nine hundred eighty-one".