978202121 has 16 divisors (see below), whose sum is σ = 1104897024. Its totient is φ = 859260864.

The previous prime is 978202109. The next prime is 978202129. The reversal of 978202121 is 121202879.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-978202121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (978202129) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50600 + ... + 67206.

It is an arithmetic number, because the mean of its divisors is an integer number (69056064).

Almost surely, 2^978202121 is an apocalyptic number.

It is an amenable number.

978202121 is a deficient number, since it is larger than the sum of its proper divisors (126694903).

978202121 is a wasteful number, since it uses less digits than its factorization.

978202121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16840.

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 978202121 is about 31276.2229337240. Note that the first 3 decimals coincide. The cubic root of 978202121 is about 992.6805973878.

The spelling of 978202121 in words is "nine hundred seventy-eight million, two hundred two thousand, one hundred twenty-one".