20535323440 has 20 divisors (see below), whose sum is σ = 47744627184. Its totient is φ = 8214129344.

The previous prime is 20535323407. The next prime is 20535323441. The reversal of 20535323440 is 4432353502.

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (20535323441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128345692 + ... + 128345851.

Almost surely, 2^20535323440 is an apocalyptic number.

20535323440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20535323440 is an abundant number, since it is smaller than the sum of its proper divisors (27209303744).

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

20535323440 is a wasteful number, since it uses less digits than its factorization.

20535323440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256691556 (or 256691550 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 31.

Adding to 20535323440 its reverse (4432353502), we get a palindrome (24967676942).

The spelling of 20535323440 in words is "twenty billion, five hundred thirty-five million, three hundred twenty-three thousand, four hundred forty".