21140431042 has 4 divisors (see below), whose sum is σ = 31710646566. Its totient is φ = 10570215520.

The previous prime is 21140431027. The next prime is 21140431043. The reversal of 21140431042 is 24013404112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20885741361 + 254689681 = 144519^2 + 15959^2 .

It is not an unprimeable number, because it can be changed into a prime (21140431043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5285107759 + ... + 5285107762.

Almost surely, 2^21140431042 is an apocalyptic number.

21140431042 is a deficient number, since it is larger than the sum of its proper divisors (10570215524).

21140431042 is a wasteful number, since it uses less digits than its factorization.

21140431042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10570215523.

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21140431042 its reverse (24013404112), we get a palindrome (45153835154).

The spelling of 21140431042 in words is "twenty-one billion, one hundred forty million, four hundred thirty-one thousand, forty-two".