220161978 has 24 divisors (see below), whose sum is σ = 488112768. Its totient is φ = 71680392.

The previous prime is 220161973. The next prime is 220161979. The reversal of 220161978 is 879161022.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (220161971) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 141450 + ... + 142997.

It is an arithmetic number, because the mean of its divisors is an integer number (20338032).

Almost surely, 2^220161978 is an apocalyptic number.

220161978 is an abundant number, since it is smaller than the sum of its proper divisors (267950790).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

220161978 is a wasteful number, since it uses less digits than its factorization.

220161978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284498 (or 284495 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 220161978 is about 14837.8562467764. The cubic root of 220161978 is about 603.8291934748.

The spelling of 220161978 in words is "two hundred twenty million, one hundred sixty-one thousand, nine hundred seventy-eight".