20408661504 has 900 divisors, whose sum is σ = 78825509532. Its totient is φ = 5237084160.

The previous prime is 20408661491. The next prime is 20408661509. The reversal of 20408661504 is 40516680402.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20408661509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 89 ways as a sum of consecutive naturals, for example, 245887447 + ... + 245887529.

Almost surely, 2^20408661504 is an apocalyptic number.

20408661504 is a gapful number since it is divisible by the number (24) 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 20408661504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39412754766).

20408661504 is an abundant number, since it is smaller than the sum of its proper divisors (58416848028).

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

20408661504 is an equidigital number, since it uses as much as digits as its factorization.

20408661504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The spelling of 20408661504 in words is "twenty billion, four hundred eight million, six hundred sixty-one thousand, five hundred four".