20142978 has 16 divisors (see below), whose sum is σ = 41143680. Its totient is φ = 6571376.

The previous prime is 20142959. The next prime is 20143007. The reversal of 20142978 is 87924102.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35433 + ... + 35996.

It is an arithmetic number, because the mean of its divisors is an integer number (2571480).

Almost surely, 2^20142978 is an apocalyptic number.

20142978 is an abundant number, since it is smaller than the sum of its proper divisors (21000702).

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

20142978 is a wasteful number, since it uses less digits than its factorization.

20142978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71481.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 20142978 is about 4488.0929134767. The cubic root of 20142978 is about 272.0870630320.

The spelling of 20142978 in words is "twenty million, one hundred forty-two thousand, nine hundred seventy-eight".