1681206538 has 16 divisors (see below), whose sum is σ = 2756973024. Its totient is φ = 762543760.

The previous prime is 1681206523. The next prime is 1681206547. The reversal of 1681206538 is 8356021861.

It is a self number, because there is not a number n which added to its sum of digits gives 1681206538.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71545 + ... + 92092.

It is an arithmetic number, because the mean of its divisors is an integer number (172310814).

Almost surely, 2^1681206538 is an apocalyptic number.

1681206538 is a deficient number, since it is larger than the sum of its proper divisors (1075766486).

1681206538 is a wasteful number, since it uses less digits than its factorization.

1681206538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164117.

The product of its (nonzero) digits is 69120, while the sum is 40.

The square root of 1681206538 is about 41002.5186787348. The cubic root of 1681206538 is about 1189.0689084721.

The spelling of 1681206538 in words is "one billion, six hundred eighty-one million, two hundred six thousand, five hundred thirty-eight".