1688780540 has 24 divisors (see below), whose sum is σ = 3595023600. Its totient is φ = 666258048.

The previous prime is 1688780539. The next prime is 1688780549. The reversal of 1688780540 is 450878861.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688780549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 576890 + ... + 579809.

It is an arithmetic number, because the mean of its divisors is an integer number (149792650).

Almost surely, 2^1688780540 is an apocalyptic number.

1688780540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1688780540 is an abundant number, since it is smaller than the sum of its proper divisors (1906243060).

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

1688780540 is a wasteful number, since it uses less digits than its factorization.

1688780540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1156781 (or 1156779 counting only the distinct ones).

The product of its (nonzero) digits is 430080, while the sum is 47.

The square root of 1688780540 is about 41094.7750936783. The cubic root of 1688780540 is about 1190.8518581003.

The spelling of 1688780540 in words is "one billion, six hundred eighty-eight million, seven hundred eighty thousand, five hundred forty".