20748023640 has 80 divisors (see below), whose sum is σ = 69736423680. Its totient is φ = 5532805440.

The previous prime is 20748023633. The next prime is 20748023651. The reversal of 20748023640 is 4632084702.

20748023640 is a `hidden beast` number, since 2 + 0 + 7 + 4 + 8 + 0 + 2 + 3 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20748023595 and 20748023604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3198616 + ... + 3205095.

It is an arithmetic number, because the mean of its divisors is an integer number (871705296).

Almost surely, 2^20748023640 is an apocalyptic number.

20748023640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20748023640 is an abundant number, since it is smaller than the sum of its proper divisors (48988400040).

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

20748023640 is a wasteful number, since it uses less digits than its factorization.

20748023640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6403734 (or 6403721 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 36.

The spelling of 20748023640 in words is "twenty billion, seven hundred forty-eight million, twenty-three thousand, six hundred forty".