20290479840 has 144 divisors (see below), whose sum is σ = 69927320736. Its totient is φ = 5357184000.

The previous prime is 20290479827. The next prime is 20290479841. The reversal of 20290479840 is 4897409202.

It is a tau number, because it is divible by the number of its divisors (144).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20290479841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 75685 + ... + 215195.

It is an arithmetic number, because the mean of its divisors is an integer number (485606394).

Almost surely, 2^20290479840 is an apocalyptic number.

20290479840 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 20290479840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34963660368).

20290479840 is an abundant number, since it is smaller than the sum of its proper divisors (49636840896).

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

20290479840 is a wasteful number, since it uses less digits than its factorization.

20290479840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139633 (or 139622 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The spelling of 20290479840 in words is "twenty billion, two hundred ninety million, four hundred seventy-nine thousand, eight hundred forty".