34128781 has 2 divisors, whose sum is σ = 34128782. Its totient is φ = 34128780.

The previous prime is 34128761. The next prime is 34128791. The reversal of 34128781 is 18782143.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27394756 + 6734025 = 5234^2 + 2595^2 .

It is a cyclic number.

It is not a de Polignac number, because 34128781 - 2⁵ = 34128749 is a prime.

It is a super-2 number, since 2×34128781² = 2329547385091922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (34128701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 17064390 + 17064391.

It is an arithmetic number, because the mean of its divisors is an integer number (17064391).

Almost surely, 2^34128781 is an apocalyptic number.

It is an amenable number.

34128781 is a deficient number, since it is larger than the sum of its proper divisors (1).

34128781 is an equidigital number, since it uses as much as digits as its factorization.

34128781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10752, while the sum is 34.

The square root of 34128781 is about 5841.9843375346. The cubic root of 34128781 is about 324.3696848463.

The spelling of 34128781 in words is "thirty-four million, one hundred twenty-eight thousand, seven hundred eighty-one".