6520400987 has 2 divisors, whose sum is σ = 6520400988. Its totient is φ = 6520400986.

The previous prime is 6520400969. The next prime is 6520401059. The reversal of 6520400987 is 7890040256.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6520400987 - 2⁶ = 6520400923 is a prime.

It is not a weakly prime, because it can be changed into another prime (6520400917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3260200493 + 3260200494.

It is an arithmetic number, because the mean of its divisors is an integer number (3260200494).

Almost surely, 2^6520400987 is an apocalyptic number.

6520400987 is a deficient number, since it is larger than the sum of its proper divisors (1).

6520400987 is an equidigital number, since it uses as much as digits as its factorization.

6520400987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 41.

The square root of 6520400987 is about 80748.9999133116. Note that the first 4 decimals coincide. The cubic root of 6520400987 is about 1868.2060241771.

The spelling of 6520400987 in words is "six billion, five hundred twenty million, four hundred thousand, nine hundred eighty-seven".