1085890661 has 4 divisors (see below), whose sum is σ = 1120919424. Its totient is φ = 1050861900.

The previous prime is 1085890643. The next prime is 1085890667. The reversal of 1085890661 is 1660985801.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1660985801 = 1951 ⋅851351.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1085890661 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 (1085890667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17514335 + ... + 17514396.

It is an arithmetic number, because the mean of its divisors is an integer number (280229856).

Almost surely, 2^1085890661 is an apocalyptic number.

It is an amenable number.

1085890661 is a deficient number, since it is larger than the sum of its proper divisors (35028763).

1085890661 is an equidigital number, since it uses as much as digits as its factorization.

1085890661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35028762.

The product of its (nonzero) digits is 103680, while the sum is 44.

The square root of 1085890661 is about 32952.8551266806. The cubic root of 1085890661 is about 1027.8475365876.

It can be divided in two parts, 10858906 and 61, that multiplied together give a palindrome (662393266).

The spelling of 1085890661 in words is "one billion, eighty-five million, eight hundred ninety thousand, six hundred sixty-one".