20105379840 has 960 divisors, whose sum is σ = 84554588160. Its totient is φ = 3963617280.

The previous prime is 20105379823. The next prime is 20105379857. The reversal of 20105379840 is 4897350102.

It is an interprime number because it is at equal distance from previous prime (20105379823) and next prime (20105379857).

It is a tau number, because it is divible by the number of its divisors (960).

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 648560625 + ... + 648560655.

It is an arithmetic number, because the mean of its divisors is an integer number (88077696).

Almost surely, 2^20105379840 is an apocalyptic number.

20105379840 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 20105379840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42277294080).

20105379840 is an abundant number, since it is smaller than the sum of its proper divisors (64449208320).

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

20105379840 is a wasteful number, since it uses less digits than its factorization.

20105379840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116 (or 90 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 39.

The spelling of 20105379840 in words is "twenty billion, one hundred five million, three hundred seventy-nine thousand, eight hundred forty".