1681557306 has 32 divisors (see below), whose sum is σ = 3951073728. Its totient is φ = 470365440.

The previous prime is 1681557281. The next prime is 1681557349. The reversal of 1681557306 is 6037551861.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 979071 + ... + 980786.

It is an arithmetic number, because the mean of its divisors is an integer number (123471054).

Almost surely, 2^1681557306 is an apocalyptic number.

1681557306 is an abundant number, since it is smaller than the sum of its proper divisors (2269516422).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1681557306 is a wasteful number, since it uses less digits than its factorization.

1681557306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1959886.

The product of its (nonzero) digits is 151200, while the sum is 42.

The square root of 1681557306 is about 41006.7958514196. The cubic root of 1681557306 is about 1189.1515987523.

The spelling of 1681557306 in words is "one billion, six hundred eighty-one million, five hundred fifty-seven thousand, three hundred six".