21010665016 has 16 divisors (see below), whose sum is σ = 42976360440. Its totient is φ = 9550302240.

The previous prime is 21010664999. The next prime is 21010665023. The reversal of 21010665016 is 61056601012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 119378691 + ... + 119378866.

Almost surely, 2^21010665016 is an apocalyptic number.

It is an amenable number.

21010665016 is an abundant number, since it is smaller than the sum of its proper divisors (21965695424).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21010665016 is a wasteful number, since it uses less digits than its factorization.

21010665016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238757574 (or 238757570 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 28.

The spelling of 21010665016 in words is "twenty-one billion, ten million, six hundred sixty-five thousand, sixteen".