1023136781 has 2 divisors, whose sum is σ = 1023136782. Its totient is φ = 1023136780.

The previous prime is 1023136771. The next prime is 1023136817. The reversal of 1023136781 is 1876313201.

Together with next prime (1023136817) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1017035881 + 6100900 = 31891^2 + 2470^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1023136781 is a prime.

It is a super-2 number, since 2×1023136781² = 2093617745270083922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1023136771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 511568390 + 511568391.

It is an arithmetic number, because the mean of its divisors is an integer number (511568391).

Almost surely, 2^1023136781 is an apocalyptic number.

It is an amenable number.

1023136781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1023136781 is an equidigital number, since it uses as much as digits as its factorization.

1023136781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 1023136781 is about 31986.5093594159. The cubic root of 1023136781 is about 1007.6535343066.

Adding to 1023136781 its reverse (1876313201), we get a palindrome (2899449982).

The spelling of 1023136781 in words is "one billion, twenty-three million, one hundred thirty-six thousand, seven hundred eighty-one".