129721783 has 2 divisors, whose sum is σ = 129721784. Its totient is φ = 129721782.

The previous prime is 129721723. The next prime is 129721811. The reversal of 129721783 is 387127921.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129721783 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129721723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64860891 + 64860892.

It is an arithmetic number, because the mean of its divisors is an integer number (64860892).

Almost surely, 2^129721783 is an apocalyptic number.

129721783 is a deficient number, since it is larger than the sum of its proper divisors (1).

129721783 is an equidigital number, since it uses as much as digits as its factorization.

129721783 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42336, while the sum is 40.

The square root of 129721783 is about 11389.5470937171. The cubic root of 129721783 is about 506.2180615323.

The spelling of 129721783 in words is "one hundred twenty-nine million, seven hundred twenty-one thousand, seven hundred eighty-three".