1639918431647 has 2 divisors, whose sum is σ = 1639918431648. Its totient is φ = 1639918431646.

The previous prime is 1639918431623. The next prime is 1639918431659. The reversal of 1639918431647 is 7461348199361.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1639918431647 - 2²² = 1639914237343 is a prime.

It is a super-2 number, since 2×1639918431647² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1639918431647.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1639918431677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 819959215823 + 819959215824.

It is an arithmetic number, because the mean of its divisors is an integer number (819959215824).

Almost surely, 2^{1639918431647} is an apocalyptic number.

1639918431647 is a deficient number, since it is larger than the sum of its proper divisors (1).

1639918431647 is an equidigital number, since it uses as much as digits as its factorization.

1639918431647 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23514624, while the sum is 62.

The spelling of 1639918431647 in words is "one trillion, six hundred thirty-nine billion, nine hundred eighteen million, four hundred thirty-one thousand, six hundred forty-seven".