2001070781 has 2 divisors, whose sum is σ = 2001070782. Its totient is φ = 2001070780.

The previous prime is 2001070763. The next prime is 2001070807. The reversal of 2001070781 is 1870701002.

It is an a-pointer prime, because the next prime (2001070807) can be obtained adding 2001070781 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1839552100 + 161518681 = 42890^2 + 12709^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001070781 - 2¹⁴ = 2001054397 is a prime.

It is a super-2 number, since 2×2001070781² = 8008568541143899922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2001070781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2001072781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000535390 + 1000535391.

It is an arithmetic number, because the mean of its divisors is an integer number (1000535391).

Almost surely, 2^2001070781 is an apocalyptic number.

It is an amenable number.

2001070781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001070781 is an equidigital number, since it uses as much as digits as its factorization.

2001070781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 784, while the sum is 26.

The square root of 2001070781 is about 44733.3296435667. The cubic root of 2001070781 is about 1260.1458596996.

Adding to 2001070781 its reverse (1870701002), we get a palindrome (3871771783).

The spelling of 2001070781 in words is "two billion, one million, seventy thousand, seven hundred eighty-one".