20195978 has 32 divisors (see below), whose sum is σ = 34836480. Its totient is φ = 8691760.

The previous prime is 20195971. The next prime is 20196049. The reversal of 20195978 is 87959102.

It is not an unprimeable number, because it can be changed into a prime (20195971) 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, 84383 + ... + 84621.

It is an arithmetic number, because the mean of its divisors is an integer number (1088640).

Almost surely, 2^20195978 is an apocalyptic number.

20195978 is a deficient number, since it is larger than the sum of its proper divisors (14640502).

20195978 is a wasteful number, since it uses less digits than its factorization.

20195978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442.

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 20195978 is about 4493.9935469469. The cubic root of 20195978 is about 272.3254916134.

It can be divided in two parts, 2019 and 5978, that added together give a palindrome (7997).

The spelling of 20195978 in words is "twenty million, one hundred ninety-five thousand, nine hundred seventy-eight".