20634621408 has 144 divisors (see below), whose sum is σ = 59963576400. Its totient is φ = 6729136128.

The previous prime is 20634621407. The next prime is 20634621439. The reversal of 20634621408 is 80412643602.

20634621408 is a `hidden beast` number, since 2 + 0 + 634 + 6 + 2 + 14 + 0 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

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 (20634621407) 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 23 ways as a sum of consecutive naturals, for example, 2871516 + ... + 2878692.

It is an arithmetic number, because the mean of its divisors is an integer number (416413725).

Almost surely, 2^20634621408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20634621408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29981788200).

20634621408 is an abundant number, since it is smaller than the sum of its proper divisors (39328954992).

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

20634621408 is a wasteful number, since it uses less digits than its factorization.

20634621408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7409 (or 7398 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The spelling of 20634621408 in words is "twenty billion, six hundred thirty-four million, six hundred twenty-one thousand, four hundred eight".