20887475537 has 2 divisors, whose sum is σ = 20887475538. Its totient is φ = 20887475536.

The previous prime is 20887475519. The next prime is 20887475549. The reversal of 20887475537 is 73557478802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19365227281 + 1522248256 = 139159^2 + 39016^2 .

It is a cyclic number.

It is not a de Polignac number, because 20887475537 - 2⁸ = 20887475281 is a prime.

It is not a weakly prime, because it can be changed into another prime (20887472537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10443737768 + 10443737769.

It is an arithmetic number, because the mean of its divisors is an integer number (10443737769).

Almost surely, 2^20887475537 is an apocalyptic number.

It is an amenable number.

20887475537 is a deficient number, since it is larger than the sum of its proper divisors (1).

20887475537 is an equidigital number, since it uses as much as digits as its factorization.

20887475537 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13171200, while the sum is 56.

The spelling of 20887475537 in words is "twenty billion, eight hundred eighty-seven million, four hundred seventy-five thousand, five hundred thirty-seven".