20143978 has 16 divisors (see below), whose sum is σ = 30910464. Its totient is φ = 9843120.

The previous prime is 20143967. The next prime is 20143979. The reversal of 20143978 is 87934102.

It is not an unprimeable number, because it can be changed into a prime (20143979) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17476 + ... + 18592.

It is an arithmetic number, because the mean of its divisors is an integer number (1931904).

Almost surely, 2^20143978 is an apocalyptic number.

20143978 is a deficient number, since it is larger than the sum of its proper divisors (10766486).

20143978 is a wasteful number, since it uses less digits than its factorization.

20143978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1317.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 20143978 is about 4488.2043179873. The cubic root of 20143978 is about 272.0915655533.

The spelling of 20143978 in words is "twenty million, one hundred forty-three thousand, nine hundred seventy-eight".