1687121942 has 16 divisors (see below), whose sum is σ = 2824949952. Its totient is φ = 749038920.

The previous prime is 1687121903. The next prime is 1687121977. The reversal of 1687121942 is 2491217861.

It is a self number, because there is not a number n which added to its sum of digits gives 1687121942.

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, 890768 + ... + 892659.

It is an arithmetic number, because the mean of its divisors is an integer number (176559372).

Almost surely, 2^1687121942 is an apocalyptic number.

1687121942 is a deficient number, since it is larger than the sum of its proper divisors (1137828010).

1687121942 is a wasteful number, since it uses less digits than its factorization.

1687121942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1783483.

The product of its digits is 48384, while the sum is 41.

The square root of 1687121942 is about 41074.5899796943. The cubic root of 1687121942 is about 1190.4618742370.

The spelling of 1687121942 in words is "one billion, six hundred eighty-seven million, one hundred twenty-one thousand, nine hundred forty-two".