21045647416 has 8 divisors (see below), whose sum is σ = 39460588920. Its totient is φ = 10522823704.

The previous prime is 21045647387. The next prime is 21045647417. The reversal of 21045647416 is 61474654012.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21045647417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1315352956 + ... + 1315352971.

It is an arithmetic number, because the mean of its divisors is an integer number (4932573615).

Almost surely, 2^21045647416 is an apocalyptic number.

It is an amenable number.

21045647416 is a deficient number, since it is larger than the sum of its proper divisors (18414941504).

21045647416 is a wasteful number, since it uses less digits than its factorization.

21045647416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2630705933 (or 2630705929 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 40.

The spelling of 21045647416 in words is "twenty-one billion, forty-five million, six hundred forty-seven thousand, four hundred sixteen".