998961 has 4 divisors (see below), whose sum is σ = 1331952. Its totient is φ = 665972.

The previous prime is 998957. The next prime is 998969. The reversal of 998961 is 169899.

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: 169899 = 3 ⋅56633.

It is a cyclic number.

It is not a de Polignac number, because 998961 - 2² = 998957 is a prime.

It is an Ulam number.

It is a D-number.

998961 is a lucky number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 998961.

It is not an unprimeable number, because it can be changed into a prime (998969) 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, 166491 + ... + 166496.

It is an arithmetic number, because the mean of its divisors is an integer number (332988).

2⁹⁹⁸⁹⁶¹ is an apocalyptic number.

It is an amenable number.

998961 is a deficient number, since it is larger than the sum of its proper divisors (332991).

998961 is a wasteful number, since it uses less digits than its factorization.

998961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332990.

The product of its digits is 34992, while the sum is 42.

The square root of 998961 is about 999.4803649897. The cubic root of 998961 is about 99.9653546651.

The spelling of 998961 in words is "nine hundred ninety-eight thousand, nine hundred sixty-one".