1987953891047 has 2 divisors, whose sum is σ = 1987953891048. Its totient is φ = 1987953891046.

The previous prime is 1987953891041. The next prime is 1987953891083. The reversal of 1987953891047 is 7401983597891.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1987953891047 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1987953891041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 993976945523 + 993976945524.

It is an arithmetic number, because the mean of its divisors is an integer number (993976945524).

Almost surely, 2^{1987953891047} is an apocalyptic number.

1987953891047 is a deficient number, since it is larger than the sum of its proper divisors (1).

1987953891047 is an equidigital number, since it uses as much as digits as its factorization.

1987953891047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 137168640, while the sum is 71.

The spelling of 1987953891047 in words is "one trillion, nine hundred eighty-seven billion, nine hundred fifty-three million, eight hundred ninety-one thousand, forty-seven".