72781783 has 2 divisors, whose sum is σ = 72781784. Its totient is φ = 72781782.

The previous prime is 72781781. The next prime is 72781829. The reversal of 72781783 is 38718727.

It is a weak prime.

It is an emirp because it is prime and its reverse (38718727) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72781783 - 2¹ = 72781781 is a prime.

Together with 72781781, it forms a pair of twin primes.

It is a zygodrome in base 6.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72781781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36390891 + 36390892.

It is an arithmetic number, because the mean of its divisors is an integer number (36390892).

Almost surely, 2^72781783 is an apocalyptic number.

72781783 is a deficient number, since it is larger than the sum of its proper divisors (1).

72781783 is an equidigital number, since it uses as much as digits as its factorization.

72781783 is an evil number, because the sum of its binary digits is even.

The product of its digits is 131712, while the sum is 43.

The square root of 72781783 is about 8531.2240036234. The cubic root of 72781783 is about 417.5170643341.

The spelling of 72781783 in words is "seventy-two million, seven hundred eighty-one thousand, seven hundred eighty-three".