20749813740 has 144 divisors (see below), whose sum is σ = 68707941120. Its totient is φ = 5242034880.

The previous prime is 20749813739. The next prime is 20749813789. The reversal of 20749813740 is 4731894702.

20749813740 is a `hidden beast` number, since 20 + 7 + 498 + 137 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 20016 + ... + 204695.

It is an arithmetic number, because the mean of its divisors is an integer number (477138480).

Almost surely, 2^20749813740 is an apocalyptic number.

20749813740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20749813740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34353970560).

20749813740 is an abundant number, since it is smaller than the sum of its proper divisors (47958127380).

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

20749813740 is a wasteful number, since it uses less digits than its factorization.

20749813740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224754 (or 224740 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The spelling of 20749813740 in words is "twenty billion, seven hundred forty-nine million, eight hundred thirteen thousand, seven hundred forty".