31378491847 has 2 divisors, whose sum is σ = 31378491848. Its totient is φ = 31378491846.

The previous prime is 31378491827. The next prime is 31378491857. The reversal of 31378491847 is 74819487313.

It is a strong prime.

It is an emirp because it is prime and its reverse (74819487313) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31378491847 - 2⁷ = 31378491719 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31378491817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15689245923 + 15689245924.

It is an arithmetic number, because the mean of its divisors is an integer number (15689245924).

Almost surely, 2^31378491847 is an apocalyptic number.

31378491847 is a deficient number, since it is larger than the sum of its proper divisors (1).

31378491847 is an equidigital number, since it uses as much as digits as its factorization.

31378491847 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4064256, while the sum is 55.

The spelling of 31378491847 in words is "thirty-one billion, three hundred seventy-eight million, four hundred ninety-one thousand, eight hundred forty-seven".