3951985213447 has 2 divisors, whose sum is σ = 3951985213448. Its totient is φ = 3951985213446.

The previous prime is 3951985213417. The next prime is 3951985213487. The reversal of 3951985213447 is 7443125891593.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3951985213447 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3951985213417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1975992606723 + 1975992606724.

It is an arithmetic number, because the mean of its divisors is an integer number (1975992606724).

Almost surely, 2^{3951985213447} is an apocalyptic number.

3951985213447 is a deficient number, since it is larger than the sum of its proper divisors (1).

3951985213447 is an equidigital number, since it uses as much as digits as its factorization.

3951985213447 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32659200, while the sum is 61.

The spelling of 3951985213447 in words is "three trillion, nine hundred fifty-one billion, nine hundred eighty-five million, two hundred thirteen thousand, four hundred forty-seven".