18803921977 has 2 divisors, whose sum is σ = 18803921978. Its totient is φ = 18803921976.

The previous prime is 18803921971. The next prime is 18803921989. The reversal of 18803921977 is 77912930881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17336725561 + 1467196416 = 131669^2 + 38304^2 .

It is a cyclic number.

It is not a de Polignac number, because 18803921977 - 2³¹ = 16656438329 is a prime.

It is not a weakly prime, because it can be changed into another prime (18803921971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9401960988 + 9401960989.

It is an arithmetic number, because the mean of its divisors is an integer number (9401960989).

Almost surely, 2^18803921977 is an apocalyptic number.

It is an amenable number.

18803921977 is a deficient number, since it is larger than the sum of its proper divisors (1).

18803921977 is an equidigital number, since it uses as much as digits as its factorization.

18803921977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1524096, while the sum is 55.

The spelling of 18803921977 in words is "eighteen billion, eight hundred three million, nine hundred twenty-one thousand, nine hundred seventy-seven".