1664445157 has 2 divisors, whose sum is σ = 1664445158. Its totient is φ = 1664445156.

The previous prime is 1664445137. The next prime is 1664445173. The reversal of 1664445157 is 7515444661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1651528321 + 12916836 = 40639^2 + 3594^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1664445157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1664445127) 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, 832222578 + 832222579.

It is an arithmetic number, because the mean of its divisors is an integer number (832222579).

Almost surely, 2^1664445157 is an apocalyptic number.

It is an amenable number.

1664445157 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664445157 is an equidigital number, since it uses as much as digits as its factorization.

1664445157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 403200, while the sum is 43.

The square root of 1664445157 is about 40797.6121482618. The cubic root of 1664445157 is about 1185.1040890840.

The spelling of 1664445157 in words is "one billion, six hundred sixty-four million, four hundred forty-five thousand, one hundred fifty-seven".