1661888439 has 12 divisors (see below), whose sum is σ = 2400912072. Its totient is φ = 1107738000.

The previous prime is 1661888419. The next prime is 1661888479. The reversal of 1661888439 is 9348881661.

1661888439 is a `hidden beast` number, since 16 + 618 + 8 + 8 + 4 + 3 + 9 = 666.

It is not a de Polignac number, because 1661888439 - 2⁷ = 1661888311 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661888419) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 59424 + ... + 82794.

It is an arithmetic number, because the mean of its divisors is an integer number (200076006).

Almost surely, 2^1661888439 is an apocalyptic number.

1661888439 is a deficient number, since it is larger than the sum of its proper divisors (739023633).

1661888439 is a wasteful number, since it uses less digits than its factorization.

1661888439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31278 (or 31275 counting only the distinct ones).

The product of its digits is 1990656, while the sum is 54.

The square root of 1661888439 is about 40766.2659437923. The cubic root of 1661888439 is about 1184.4969739149.

The spelling of 1661888439 in words is "one billion, six hundred sixty-one million, eight hundred eighty-eight thousand, four hundred thirty-nine".