142686521 has 4 divisors (see below), whose sum is σ = 147289344. Its totient is φ = 138083700.

The previous prime is 142686517. The next prime is 142686527. The reversal of 142686521 is 125686241.

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: 125686241 = 6473 ⋅19417.

It is a cyclic number.

It is not a de Polignac number, because 142686521 - 2² = 142686517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (142686527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2301365 + ... + 2301426.

It is an arithmetic number, because the mean of its divisors is an integer number (36822336).

Almost surely, 2^142686521 is an apocalyptic number.

It is an amenable number.

142686521 is a deficient number, since it is larger than the sum of its proper divisors (4602823).

142686521 is an equidigital number, since it uses as much as digits as its factorization.

142686521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4602822.

The product of its digits is 23040, while the sum is 35.

The square root of 142686521 is about 11945.1463364833. The cubic root of 142686521 is about 522.5497564851.

The spelling of 142686521 in words is "one hundred forty-two million, six hundred eighty-six thousand, five hundred twenty-one".