20860991940 has 48 divisors (see below), whose sum is σ = 58496413248. Its totient is φ = 5554775424.

The previous prime is 20860991909. The next prime is 20860991947. The reversal of 20860991940 is 4919906802.

It is a self number, because there is not a number n which added to its sum of digits gives 20860991940.

It is not an unprimeable number, because it can be changed into a prime (20860991947) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 213547 + ... + 295506.

It is an arithmetic number, because the mean of its divisors is an integer number (1218675276).

Almost surely, 2^20860991940 is an apocalyptic number.

20860991940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20860991940 is an abundant number, since it is smaller than the sum of its proper divisors (37635421308).

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

20860991940 is a wasteful number, since it uses less digits than its factorization.

20860991940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 509748 (or 509746 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 48.

The spelling of 20860991940 in words is "twenty billion, eight hundred sixty million, nine hundred ninety-one thousand, nine hundred forty".