20018001977 has 2 divisors, whose sum is σ = 20018001978. Its totient is φ = 20018001976.

The previous prime is 20018001973. The next prime is 20018002021. The reversal of 20018001977 is 77910081002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11631838201 + 8386163776 = 107851^2 + 91576^2 .

It is a cyclic number.

It is not a de Polignac number, because 20018001977 - 2² = 20018001973 is a prime.

It is not a weakly prime, because it can be changed into another prime (20018001973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10009000988 + 10009000989.

It is an arithmetic number, because the mean of its divisors is an integer number (10009000989).

Almost surely, 2^20018001977 is an apocalyptic number.

It is an amenable number.

20018001977 is a deficient number, since it is larger than the sum of its proper divisors (1).

20018001977 is an equidigital number, since it uses as much as digits as its factorization.

20018001977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7056, while the sum is 35.

Adding to 20018001977 its reverse (77910081002), we get a palindrome (97928082979).

The spelling of 20018001977 in words is "twenty billion, eighteen million, one thousand, nine hundred seventy-seven".