21421107628 has 6 divisors (see below), whose sum is σ = 37486938356. Its totient is φ = 10710553812.

The previous prime is 21421107577. The next prime is 21421107629. The reversal of 21421107628 is 82670112412.

It is a junction number, because it is equal to n+sod(n) for n = 21421107593 and 21421107602.

It is not an unprimeable number, because it can be changed into a prime (21421107629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2677638450 + ... + 2677638457.

Almost surely, 2^21421107628 is an apocalyptic number.

It is an amenable number.

21421107628 is a deficient number, since it is larger than the sum of its proper divisors (16065830728).

21421107628 is a wasteful number, since it uses less digits than its factorization.

21421107628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5355276911 (or 5355276909 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 34.

The spelling of 21421107628 in words is "twenty-one billion, four hundred twenty-one million, one hundred seven thousand, six hundred twenty-eight".