20401109977 has 2 divisors, whose sum is σ = 20401109978. Its totient is φ = 20401109976.

The previous prime is 20401109923. The next prime is 20401109999. The reversal of 20401109977 is 77990110402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19906670281 + 494439696 = 141091^2 + 22236^2 .

It is a cyclic number.

It is not a de Polignac number, because 20401109977 - 2²³ = 20392721369 is a prime.

It is not a weakly prime, because it can be changed into another prime (20401103977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10200554988 + 10200554989.

It is an arithmetic number, because the mean of its divisors is an integer number (10200554989).

Almost surely, 2^20401109977 is an apocalyptic number.

It is an amenable number.

20401109977 is a deficient number, since it is larger than the sum of its proper divisors (1).

20401109977 is an equidigital number, since it uses as much as digits as its factorization.

20401109977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31752, while the sum is 40.

The spelling of 20401109977 in words is "twenty billion, four hundred one million, one hundred nine thousand, nine hundred seventy-seven".