142199978 has 4 divisors (see below), whose sum is σ = 213299970. Its totient is φ = 71099988.

The previous prime is 142199977. The next prime is 142200041. The reversal of 142199978 is 879991241.

142199978 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 879991241 = 41 ⋅21463201.

It can be written as a sum of positive squares in only one way, i.e., 111872929 + 30327049 = 10577^2 + 5507^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (142199977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35549993 + ... + 35549996.

Almost surely, 2^142199978 is an apocalyptic number.

142199978 is a deficient number, since it is larger than the sum of its proper divisors (71099992).

142199978 is an equidigital number, since it uses as much as digits as its factorization.

142199978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71099991.

The product of its digits is 326592, while the sum is 50.

The square root of 142199978 is about 11924.7632261609. The cubic root of 142199978 is about 521.9551372414.

The spelling of 142199978 in words is "one hundred forty-two million, one hundred ninety-nine thousand, nine hundred seventy-eight".