20787715648 has 28 divisors (see below), whose sum is σ = 47143570432. Its totient is φ = 8909020800.

The previous prime is 20787715607. The next prime is 20787715693. The reversal of 20787715648 is 84651778702.

It is a tau number, because it is divible by the number of its divisors (28).

It is a super-3 number, since 3×20787715648³ (a number of 32 digits) contains 333 as substring.

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, 23200128 + ... + 23201023.

It is an arithmetic number, because the mean of its divisors is an integer number (1683698944).

Almost surely, 2^20787715648 is an apocalyptic number.

20787715648 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20787715648 is an abundant number, since it is smaller than the sum of its proper divisors (26355854784).

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

20787715648 is an equidigital number, since it uses as much as digits as its factorization.

20787715648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46401170 (or 46401160 counting only the distinct ones).

The product of its (nonzero) digits is 5268480, while the sum is 55.

The spelling of 20787715648 in words is "twenty billion, seven hundred eighty-seven million, seven hundred fifteen thousand, six hundred forty-eight".