1543142421 has 20 divisors (see below), whose sum is σ = 2308135500. Its totient is φ = 1027446336.

The previous prime is 1543142389. The next prime is 1543142443. The reversal of 1543142421 is 1242413451.

It can be written as a sum of positive squares in 2 ways, for example, as 524639025 + 1018503396 = 22905^2 + 31914^2 .

It is not a de Polignac number, because 1543142421 - 2⁵ = 1543142389 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1543147421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 53755 + ... + 77303.

It is an arithmetic number, because the mean of its divisors is an integer number (115406775).

Almost surely, 2^1543142421 is an apocalyptic number.

It is an amenable number.

1543142421 is a deficient number, since it is larger than the sum of its proper divisors (764993079).

1543142421 is an equidigital number, since it uses as much as digits as its factorization.

1543142421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24370 (or 24361 counting only the distinct ones).

The product of its digits is 3840, while the sum is 27.

The square root of 1543142421 is about 39282.8514876403. The cubic root of 1543142421 is about 1155.5852860903.

Adding to 1543142421 its reverse (1242413451), we get a palindrome (2785555872).

The spelling of 1543142421 in words is "one billion, five hundred forty-three million, one hundred forty-two thousand, four hundred twenty-one".