142821 has 12 divisors (see below), whose sum is σ = 235872. Its totient is φ = 81576.

The previous prime is 142811. The next prime is 142837. The reversal of 142821 is 128241.

It is not a de Polignac number, because 142821 - 2⁵ = 142789 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 142794 and 142803.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 142821.

It is not an unprimeable number, because it can be changed into a prime (142811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1071 + ... + 1196.

It is an arithmetic number, because the mean of its divisors is an integer number (19656).

2¹⁴²⁸²¹ is an apocalyptic number.

It is an amenable number.

142821 is a deficient number, since it is larger than the sum of its proper divisors (93051).

142821 is a wasteful number, since it uses less digits than its factorization.

142821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2280 (or 2277 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

The square root of 142821 is about 377.9166574789. The cubic root of 142821 is about 52.2713868935.

Multiplying 142821 by its sum of digits (18), we get a triangular number (2570778 = T₂₂₆₇).

The spelling of 142821 in words is "one hundred forty-two thousand, eight hundred twenty-one".