891542661 has 4 divisors (see below), whose sum is σ = 1188723552. Its totient is φ = 594361772.

The previous prime is 891542657. The next prime is 891542683. The reversal of 891542661 is 166245198.

891542661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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.

It is a cyclic number.

It is not a de Polignac number, because 891542661 - 2² = 891542657 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891542161) 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, 148590441 + ... + 148590446.

It is an arithmetic number, because the mean of its divisors is an integer number (297180888).

Almost surely, 2^891542661 is an apocalyptic number.

It is an amenable number.

891542661 is a deficient number, since it is larger than the sum of its proper divisors (297180891).

891542661 is a wasteful number, since it uses less digits than its factorization.

891542661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297180890.

The product of its digits is 103680, while the sum is 42.

The square root of 891542661 is about 29858.7116433379. The cubic root of 891542661 is about 962.4556133126.

The spelling of 891542661 in words is "eight hundred ninety-one million, five hundred forty-two thousand, six hundred sixty-one".