1661257584 has 90 divisors (see below), whose sum is σ = 5408292240. Its totient is φ = 474643008.

The previous prime is 1661257573. The next prime is 1661257603. The reversal of 1661257584 is 4857521661.

1661257584 is a `hidden beast` number, since 1 + 6 + 6 + 12 + 57 + 584 = 666.

It is a congruent number.

It is an unprimeable number.

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 17 ways as a sum of consecutive naturals, for example, 110664 + ... + 124775.

It is an arithmetic number, because the mean of its divisors is an integer number (60092136).

Almost surely, 2^1661257584 is an apocalyptic number.

1661257584 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1661257584 is an abundant number, since it is smaller than the sum of its proper divisors (3747034656).

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

1661257584 is a wasteful number, since it uses less digits than its factorization.

1661257584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235467 (or 235451 counting only the distinct ones).

The product of its digits is 403200, while the sum is 45.

The square root of 1661257584 is about 40758.5277457368. The cubic root of 1661257584 is about 1184.3470760853.

The spelling of 1661257584 in words is "one billion, six hundred sixty-one million, two hundred fifty-seven thousand, five hundred eighty-four".