1610781993 has 6 divisors (see below), whose sum is σ = 2326685114. Its totient is φ = 1073854656.

The previous prime is 1610781983. The next prime is 1610782009. The reversal of 1610781993 is 3991870161.

It can be written as a sum of positive squares in only one way, i.e., 1383616809 + 227165184 = 37197^2 + 15072^2 .

It is not a de Polignac number, because 1610781993 - 2⁵ = 1610781961 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1610781973) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 89487880 + ... + 89487897.

Almost surely, 2^1610781993 is an apocalyptic number.

It is an amenable number.

1610781993 is a deficient number, since it is larger than the sum of its proper divisors (715903121).

1610781993 is a wasteful number, since it uses less digits than its factorization.

1610781993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178975783 (or 178975780 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 1610781993 is about 40134.5486208578. The cubic root of 1610781993 is about 1172.2284441043.

The spelling of 1610781993 in words is "one billion, six hundred ten million, seven hundred eighty-one thousand, nine hundred ninety-three".