1689400660 has 12 divisors (see below), whose sum is σ = 3547741428. Its totient is φ = 675760256.

The previous prime is 1689400621. The next prime is 1689400663. The reversal of 1689400660 is 660049861.

It can be written as a sum of positive squares in 2 ways, for example, as 1062499216 + 626901444 = 32596^2 + 25038^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1689400663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42234997 + ... + 42235036.

It is an arithmetic number, because the mean of its divisors is an integer number (295645119).

Almost surely, 2^1689400660 is an apocalyptic number.

1689400660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1689400660 is an abundant number, since it is smaller than the sum of its proper divisors (1858340768).

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

1689400660 is a wasteful number, since it uses less digits than its factorization.

1689400660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84470042 (or 84470040 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 1689400660 is about 41102.3193992748. The cubic root of 1689400660 is about 1190.9976004800.

The spelling of 1689400660 in words is "one billion, six hundred eighty-nine million, four hundred thousand, six hundred sixty".