20499999999977 has 2 divisors, whose sum is σ = 20499999999978. Its totient is φ = 20499999999976.

The previous prime is 20499999999917. The next prime is 20500000000001. The reversal of 20499999999977 is 77999999999402.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20493629406121 + 6370593856 = 4526989^2 + 79816^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20499999999977 is a prime.

It is not a weakly prime, because it can be changed into another prime (20499999999917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10249999999988 + 10249999999989.

It is an arithmetic number, because the mean of its divisors is an integer number (10249999999989).

Almost surely, 2^{20499999999977} is an apocalyptic number.

It is an amenable number.

20499999999977 is a deficient number, since it is larger than the sum of its proper divisors (1).

20499999999977 is an equidigital number, since it uses as much as digits as its factorization.

20499999999977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 151868831688, while the sum is 101.

The spelling of 20499999999977 in words is "twenty trillion, four hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred seventy-seven".