1661027685 has 32 divisors (see below), whose sum is σ = 2825549568. Its totient is φ = 831367680.

The previous prime is 1661027663. The next prime is 1661027699. The reversal of 1661027685 is 5867201661.

It is not a de Polignac number, because 1661027685 - 2⁸ = 1661027429 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27136 + ... + 63705.

It is an arithmetic number, because the mean of its divisors is an integer number (88298424).

Almost surely, 2^1661027685 is an apocalyptic number.

1661027685 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1661027685 is a deficient number, since it is larger than the sum of its proper divisors (1164521883).

1661027685 is a wasteful number, since it uses less digits than its factorization.

1661027685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90925.

The product of its (nonzero) digits is 120960, while the sum is 42.

The square root of 1661027685 is about 40755.7073917261. The cubic root of 1661027685 is about 1184.2924402134.

The spelling of 1661027685 in words is "one billion, six hundred sixty-one million, twenty-seven thousand, six hundred eighty-five".