20477974987 has 2 divisors, whose sum is σ = 20477974988. Its totient is φ = 20477974986.

The previous prime is 20477974981. The next prime is 20477975051. The reversal of 20477974987 is 78947977402.

It is an a-pointer prime, because the next prime (20477975051) can be obtained adding 20477974987 to its sum of digits (64).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20477974987 - 2¹¹ = 20477972939 is a prime.

It is not a weakly prime, because it can be changed into another prime (20477974981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10238987493 + 10238987494.

It is an arithmetic number, because the mean of its divisors is an integer number (10238987494).

Almost surely, 2^20477974987 is an apocalyptic number.

20477974987 is a deficient number, since it is larger than the sum of its proper divisors (1).

20477974987 is an equidigital number, since it uses as much as digits as its factorization.

20477974987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 49787136, while the sum is 64.

The spelling of 20477974987 in words is "twenty billion, four hundred seventy-seven million, nine hundred seventy-four thousand, nine hundred eighty-seven".