121978 has 8 divisors (see below), whose sum is σ = 185760. Its totient is φ = 60060.

The previous prime is 121967. The next prime is 121993. The reversal of 121978 is 879121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 288 + ... + 571.

It is an arithmetic number, because the mean of its divisors is an integer number (23220).

2¹²¹⁹⁷⁸ is an apocalyptic number.

121978 is a deficient number, since it is larger than the sum of its proper divisors (63782).

121978 is an equidigital number, since it uses as much as digits as its factorization.

121978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 932.

The product of its digits is 1008, while the sum is 28.

The square root of 121978 is about 349.2534896032. The cubic root of 121978 is about 49.5937752334.

The spelling of 121978 in words is "one hundred twenty-one thousand, nine hundred seventy-eight".