1606981257 has 48 divisors (see below), whose sum is σ = 2682695808. Its totient is φ = 907994880.

The previous prime is 1606981247. The next prime is 1606981267. The reversal of 1606981257 is 7521896061.

It is an interprime number because it is at equal distance from previous prime (1606981247) and next prime (1606981267).

It is not a de Polignac number, because 1606981257 - 2¹² = 1606977161 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1606981217) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3084157 + ... + 3084677.

It is an arithmetic number, because the mean of its divisors is an integer number (55889496).

Almost surely, 2^1606981257 is an apocalyptic number.

It is an amenable number.

1606981257 is a deficient number, since it is larger than the sum of its proper divisors (1075714551).

1606981257 is a wasteful number, since it uses less digits than its factorization.

1606981257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 990 (or 987 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The square root of 1606981257 is about 40087.1707283016. The cubic root of 1606981257 is about 1171.3057370643.

The spelling of 1606981257 in words is "one billion, six hundred six million, nine hundred eighty-one thousand, two hundred fifty-seven".