21770779903 has 2 divisors, whose sum is σ = 21770779904. Its totient is φ = 21770779902.

The previous prime is 21770779873. The next prime is 21770779939. The reversal of 21770779903 is 30997707712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21770779903 - 2¹⁷ = 21770648831 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21770774903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10885389951 + 10885389952.

It is an arithmetic number, because the mean of its divisors is an integer number (10885389952).

Almost surely, 2^21770779903 is an apocalyptic number.

21770779903 is a deficient number, since it is larger than the sum of its proper divisors (1).

21770779903 is an equidigital number, since it uses as much as digits as its factorization.

21770779903 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1166886, while the sum is 52.

The spelling of 21770779903 in words is "twenty-one billion, seven hundred seventy million, seven hundred seventy-nine thousand, nine hundred three".