1661902887 has 16 divisors (see below), whose sum is σ = 2343566720. Its totient is φ = 1044640800.

The previous prime is 1661902883. The next prime is 1661902903. The reversal of 1661902887 is 7882091661.

It is not a de Polignac number, because 1661902887 - 2² = 1661902883 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 (1661902883) 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 15 ways as a sum of consecutive naturals, for example, 57064 + ... + 81117.

It is an arithmetic number, because the mean of its divisors is an integer number (146472920).

Almost surely, 2^1661902887 is an apocalyptic number.

1661902887 is a deficient number, since it is larger than the sum of its proper divisors (681663833).

1661902887 is a wasteful number, since it uses less digits than its factorization.

1661902887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138414.

The product of its (nonzero) digits is 290304, while the sum is 48.

The square root of 1661902887 is about 40766.4431487467. The cubic root of 1661902887 is about 1184.5004064684.

The spelling of 1661902887 in words is "one billion, six hundred sixty-one million, nine hundred two thousand, eight hundred eighty-seven".