20311302440 has 128 divisors (see below), whose sum is σ = 55141672320. Its totient is φ = 6633446400.

The previous prime is 20311302439. The next prime is 20311302457. The reversal of 20311302440 is 4420311302.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 163655 + ... + 259625.

It is an arithmetic number, because the mean of its divisors is an integer number (430794315).

Almost surely, 2^20311302440 is an apocalyptic number.

20311302440 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 20311302440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27570836160).

20311302440 is an abundant number, since it is smaller than the sum of its proper divisors (34830369880).

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

20311302440 is a wasteful number, since it uses less digits than its factorization.

20311302440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96043 (or 96039 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 20311302440 its reverse (4420311302), we get a palindrome (24731613742).

The spelling of 20311302440 in words is "twenty billion, three hundred eleven million, three hundred two thousand, four hundred forty".