29781139 has 2 divisors, whose sum is σ = 29781140. Its totient is φ = 29781138.

The previous prime is 29781133. The next prime is 29781179. The reversal of 29781139 is 93118792.

It is an a-pointer prime, because the next prime (29781179) can be obtained adding 29781139 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 29781139 - 2³ = 29781131 is a prime.

It is not a weakly prime, because it can be changed into another prime (29781131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14890569 + 14890570.

It is an arithmetic number, because the mean of its divisors is an integer number (14890570).

Almost surely, 2^29781139 is an apocalyptic number.

29781139 is a deficient number, since it is larger than the sum of its proper divisors (1).

29781139 is an equidigital number, since it uses as much as digits as its factorization.

29781139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27216, while the sum is 40.

The square root of 29781139 is about 5457.2098182130. The cubic root of 29781139 is about 309.9657922712.

The spelling of 29781139 in words is "twenty-nine million, seven hundred eighty-one thousand, one hundred thirty-nine".