20001977 has 2 divisors, whose sum is σ = 20001978. Its totient is φ = 20001976.

The previous prime is 20001959. The next prime is 20001983. The reversal of 20001977 is 77910002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18826921 + 1175056 = 4339^2 + 1084^2 .

It is a cyclic number.

It is not a de Polignac number, because 20001977 - 2²⁰ = 18953401 is a prime.

It is not a weakly prime, because it can be changed into another prime (20001937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000988 + 10000989.

It is an arithmetic number, because the mean of its divisors is an integer number (10000989).

Almost surely, 2^20001977 is an apocalyptic number.

It is an amenable number.

20001977 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001977 is an equidigital number, since it uses as much as digits as its factorization.

20001977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 882, while the sum is 26.

The square root of 20001977 is about 4472.3569848571. The cubic root of 20001977 is about 271.4507053708.

Adding to 20001977 its reverse (77910002), we get a palindrome (97911979).

The spelling of 20001977 in words is "twenty million, one thousand, nine hundred seventy-seven".