1681451887 has 2 divisors, whose sum is σ = 1681451888. Its totient is φ = 1681451886.

The previous prime is 1681451881. The next prime is 1681451897. The reversal of 1681451887 is 7881541861.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1681451887 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1681451887.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1681451881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840725943 + 840725944.

It is an arithmetic number, because the mean of its divisors is an integer number (840725944).

Almost surely, 2^1681451887 is an apocalyptic number.

1681451887 is a deficient number, since it is larger than the sum of its proper divisors (1).

1681451887 is an equidigital number, since it uses as much as digits as its factorization.

1681451887 is an evil number, because the sum of its binary digits is even.

The product of its digits is 430080, while the sum is 49.

The square root of 1681451887 is about 41005.5104467680. The cubic root of 1681451887 is about 1189.1267484163.

The spelling of 1681451887 in words is "one billion, six hundred eighty-one million, four hundred fifty-one thousand, eight hundred eighty-seven".