20545404240 has 80 divisors (see below), whose sum is σ = 63955210176. Its totient is φ = 5456025600.

The previous prime is 20545404239. The next prime is 20545404251. The reversal of 20545404240 is 4240454502.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×20545404240² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 20545404198 and 20545404207.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 119766 + ... + 235445.

Almost surely, 2^20545404240 is an apocalyptic number.

20545404240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20545404240 is an abundant number, since it is smaller than the sum of its proper divisors (43409805936).

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

20545404240 is a wasteful number, since it uses less digits than its factorization.

20545404240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355468 (or 355462 counting only the distinct ones).

The product of its (nonzero) digits is 25600, while the sum is 30.

Adding to 20545404240 its reverse (4240454502), we get a palindrome (24785858742).

The spelling of 20545404240 in words is "twenty billion, five hundred forty-five million, four hundred four thousand, two hundred forty".