21131442028 has 6 divisors (see below), whose sum is σ = 36980023556. Its totient is φ = 10565721012.

The previous prime is 21131442023. The next prime is 21131442053. The reversal of 21131442028 is 82024413112.

It is a junction number, because it is equal to n+sod(n) for n = 21131441987 and 21131442005.

It is not an unprimeable number, because it can be changed into a prime (21131442023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2641430250 + ... + 2641430257.

Almost surely, 2^21131442028 is an apocalyptic number.

It is an amenable number.

21131442028 is a deficient number, since it is larger than the sum of its proper divisors (15848581528).

21131442028 is a wasteful number, since it uses less digits than its factorization.

21131442028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5282860511 (or 5282860509 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The spelling of 21131442028 in words is "twenty-one billion, one hundred thirty-one million, four hundred forty-two thousand, twenty-eight".