20772744640 has 56 divisors (see below), whose sum is σ = 49540436352. Its totient is φ = 8296442880.

The previous prime is 20772744611. The next prime is 20772744649. The reversal of 20772744640 is 4644727702.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20772744649) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 162417 + ... + 260623.

Almost surely, 2^20772744640 is an apocalyptic number.

20772744640 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 20772744640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24770218176).

20772744640 is an abundant number, since it is smaller than the sum of its proper divisors (28767691712).

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

20772744640 is an equidigital number, since it uses as much as digits as its factorization.

20772744640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98885 (or 98875 counting only the distinct ones).

The product of its (nonzero) digits is 526848, while the sum is 43.

The spelling of 20772744640 in words is "twenty billion, seven hundred seventy-two million, seven hundred forty-four thousand, six hundred forty".