1642063991 has 2 divisors, whose sum is σ = 1642063992. Its totient is φ = 1642063990.

The previous prime is 1642063979. The next prime is 1642063993. The reversal of 1642063991 is 1993602461.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1642063991 - 2¹⁰ = 1642062967 is a prime.

Together with 1642063993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1642063993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 821031995 + 821031996.

It is an arithmetic number, because the mean of its divisors is an integer number (821031996).

Almost surely, 2^1642063991 is an apocalyptic number.

1642063991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1642063991 is an equidigital number, since it uses as much as digits as its factorization.

1642063991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 41.

The square root of 1642063991 is about 40522.3887622633. The cubic root of 1642063991 is about 1179.7682181446.

The spelling of 1642063991 in words is "one billion, six hundred forty-two million, sixty-three thousand, nine hundred ninety-one".