1680388901 has 4 divisors (see below), whose sum is σ = 1753449312. Its totient is φ = 1607328492.

The previous prime is 1680388889. The next prime is 1680388939. The reversal of 1680388901 is 1098830861.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1098830861 = 71 ⋅15476491.

It is a cyclic number.

It is not a de Polignac number, because 1680388901 - 2⁶ = 1680388837 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1680388991) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 36530171 + ... + 36530216.

It is an arithmetic number, because the mean of its divisors is an integer number (438362328).

Almost surely, 2^1680388901 is an apocalyptic number.

It is an amenable number.

1680388901 is a deficient number, since it is larger than the sum of its proper divisors (73060411).

1680388901 is an equidigital number, since it uses as much as digits as its factorization.

1680388901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73060410.

The product of its (nonzero) digits is 82944, while the sum is 44.

The square root of 1680388901 is about 40992.5468957468. The cubic root of 1680388901 is about 1188.8761135227.

The spelling of 1680388901 in words is "one billion, six hundred eighty million, three hundred eighty-eight thousand, nine hundred one".