1687122640 has 40 divisors (see below), whose sum is σ = 4482927360. Its totient is φ = 578441856.

The previous prime is 1687122631. The next prime is 1687122691. The reversal of 1687122640 is 462217861.

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 1687122640.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1505800 + ... + 1506919.

It is an arithmetic number, because the mean of its divisors is an integer number (112073184).

Almost surely, 2^1687122640 is an apocalyptic number.

1687122640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1687122640 is an abundant number, since it is smaller than the sum of its proper divisors (2795804720).

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

1687122640 is a wasteful number, since it uses less digits than its factorization.

1687122640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3012739 (or 3012733 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 1687122640 is about 41074.5984764307. The cubic root of 1687122640 is about 1190.4620384106.

The spelling of 1687122640 in words is "one billion, six hundred eighty-seven million, one hundred twenty-two thousand, six hundred forty".