1646642047 has 2 divisors, whose sum is σ = 1646642048. Its totient is φ = 1646642046.

The previous prime is 1646642029. The next prime is 1646642099. The reversal of 1646642047 is 7402466461.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1646642047 is a prime.

It is a super-2 number, since 2×1646642047² = 5422860061896700418, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1646642147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 823321023 + 823321024.

It is an arithmetic number, because the mean of its divisors is an integer number (823321024).

Almost surely, 2^1646642047 is an apocalyptic number.

1646642047 is a deficient number, since it is larger than the sum of its proper divisors (1).

1646642047 is an equidigital number, since it uses as much as digits as its factorization.

1646642047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 193536, while the sum is 40.

The square root of 1646642047 is about 40578.8374279008. The cubic root of 1646642047 is about 1180.8635943314.

The spelling of 1646642047 in words is "one billion, six hundred forty-six million, six hundred forty-two thousand, forty-seven".