21012412142 has 4 divisors (see below), whose sum is σ = 31518618216. Its totient is φ = 10506206070.

The previous prime is 21012412117. The next prime is 21012412177. The reversal of 21012412142 is 24121421012.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5253103034 + ... + 5253103037.

It is an arithmetic number, because the mean of its divisors is an integer number (7879654554).

Almost surely, 2^21012412142 is an apocalyptic number.

21012412142 is a deficient number, since it is larger than the sum of its proper divisors (10506206074).

21012412142 is a wasteful number, since it uses less digits than its factorization.

21012412142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10506206073.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21012412142 its reverse (24121421012), we get a palindrome (45133833154).

The spelling of 21012412142 in words is "twenty-one billion, twelve million, four hundred twelve thousand, one hundred forty-two".