142809991 has 2 divisors, whose sum is σ = 142809992. Its totient is φ = 142809990.

The previous prime is 142809983. The next prime is 142810051. The reversal of 142809991 is 199908241.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 142809991 - 2³ = 142809983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (142809941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 71404995 + 71404996.

It is an arithmetic number, because the mean of its divisors is an integer number (71404996).

Almost surely, 2^142809991 is an apocalyptic number.

142809991 is a deficient number, since it is larger than the sum of its proper divisors (1).

142809991 is an equidigital number, since it uses as much as digits as its factorization.

142809991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 43.

The square root of 142809991 is about 11950.3134268520. The cubic root of 142809991 is about 522.7004378924.

The spelling of 142809991 in words is "one hundred forty-two million, eight hundred nine thousand, nine hundred ninety-one".