983691661 has 4 divisors (see below), whose sum is σ = 983806912. Its totient is φ = 983576412.

The previous prime is 983691649. The next prime is 983691691. The reversal of 983691661 is 166196389.

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 983691661 - 2¹⁹ = 983167373 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 (983691641) 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, 43701 + ... + 62266.

It is an arithmetic number, because the mean of its divisors is an integer number (245951728).

Almost surely, 2^983691661 is an apocalyptic number.

It is an amenable number.

983691661 is a deficient number, since it is larger than the sum of its proper divisors (115251).

983691661 is a wasteful number, since it uses less digits than its factorization.

983691661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115250.

The product of its digits is 419904, while the sum is 49.

The square root of 983691661 is about 31363.8591534907. The cubic root of 983691661 is about 994.5340649887.

The spelling of 983691661 in words is "nine hundred eighty-three million, six hundred ninety-one thousand, six hundred sixty-one".