20609221978 has 8 divisors (see below), whose sum is σ = 31420617300. Its totient is φ = 10135682880.

The previous prime is 20609221951. The next prime is 20609222027. The reversal of 20609221978 is 87912290602.

It can be written as a sum of positive squares in 2 ways, for example, as 17968598209 + 2640623769 = 134047^2 + 51387^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84463903 + ... + 84464146.

Almost surely, 2^20609221978 is an apocalyptic number.

20609221978 is a deficient number, since it is larger than the sum of its proper divisors (10811395322).

20609221978 is a wasteful number, since it uses less digits than its factorization.

20609221978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168928112.

The product of its (nonzero) digits is 217728, while the sum is 46.

The spelling of 20609221978 in words is "twenty billion, six hundred nine million, two hundred twenty-one thousand, nine hundred seventy-eight".