142400021 has 2 divisors, whose sum is σ = 142400022. Its totient is φ = 142400020.

The previous prime is 142400009. The next prime is 142400053. The reversal of 142400021 is 120004241.

142400021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 123520996 + 18879025 = 11114^2 + 4345^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-142400021 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 142399969 and 142400005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (142409021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 71200010 + 71200011.

It is an arithmetic number, because the mean of its divisors is an integer number (71200011).

Almost surely, 2^142400021 is an apocalyptic number.

It is an amenable number.

142400021 is a deficient number, since it is larger than the sum of its proper divisors (1).

142400021 is an equidigital number, since it uses as much as digits as its factorization.

142400021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 142400021 is about 11933.1479920430. The cubic root of 142400021 is about 522.1997799135.

Adding to 142400021 its reverse (120004241), we get a palindrome (262404262).

The spelling of 142400021 in words is "one hundred forty-two million, four hundred thousand, twenty-one".