21478647708 has 36 divisors (see below), whose sum is σ = 62049427440. Its totient is φ = 6136756416.

The previous prime is 21478647703. The next prime is 21478647731. The reversal of 21478647708 is 80774687412.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×21478647708² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21478647703) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42616113 + ... + 42616616.

Almost surely, 2^21478647708 is an apocalyptic number.

21478647708 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21478647708 is an abundant number, since it is smaller than the sum of its proper divisors (40570779732).

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

21478647708 is a wasteful number, since it uses less digits than its factorization.

21478647708 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85232746 (or 85232741 counting only the distinct ones).

The product of its (nonzero) digits is 4214784, while the sum is 54.

The spelling of 21478647708 in words is "twenty-one billion, four hundred seventy-eight million, six hundred forty-seven thousand, seven hundred eight".