142538809 has 4 divisors (see below), whose sum is σ = 162901504. Its totient is φ = 122176116.

The previous prime is 142538807. The next prime is 142538813. The reversal of 142538809 is 908835241.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 908835241 = 127 ⋅7156183.

It is a cyclic number.

It is not a de Polignac number, because 142538809 - 2¹ = 142538807 is a prime.

It is a super-2 number, since 2×142538809² = 40634624142276962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (142538807) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10181337 + ... + 10181350.

It is an arithmetic number, because the mean of its divisors is an integer number (40725376).

Almost surely, 2^142538809 is an apocalyptic number.

It is an amenable number.

142538809 is a deficient number, since it is larger than the sum of its proper divisors (20362695).

142538809 is an equidigital number, since it uses as much as digits as its factorization.

142538809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20362694.

The product of its (nonzero) digits is 69120, while the sum is 40.

The square root of 142538809 is about 11938.9618057853. The cubic root of 142538809 is about 522.3693761671.

The spelling of 142538809 in words is "one hundred forty-two million, five hundred thirty-eight thousand, eight hundred nine".