1669398725887 has 2 divisors, whose sum is σ = 1669398725888. Its totient is φ = 1669398725886.

The previous prime is 1669398725849. The next prime is 1669398725983. The reversal of 1669398725887 is 7885278939661.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1669398725887 - 2¹⁹ = 1669398201599 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1669398725807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 834699362943 + 834699362944.

It is an arithmetic number, because the mean of its divisors is an integer number (834699362944).

Almost surely, 2^{1669398725887} is an apocalyptic number.

1669398725887 is a deficient number, since it is larger than the sum of its proper divisors (1).

1669398725887 is an equidigital number, since it uses as much as digits as its factorization.

1669398725887 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2194698240, while the sum is 79.

The spelling of 1669398725887 in words is "one trillion, six hundred sixty-nine billion, three hundred ninety-eight million, seven hundred twenty-five thousand, eight hundred eighty-seven".