20459906640 has 400 divisors, whose sum is σ = 76225121280. Its totient is φ = 5067878400.

The previous prime is 20459906573. The next prime is 20459906641. The reversal of 20459906640 is 4660995402.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20459906641) 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 79 ways as a sum of consecutive naturals, for example, 8701465 + ... + 8703815.

Almost surely, 2^20459906640 is an apocalyptic number.

20459906640 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 20459906640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38112560640).

20459906640 is an abundant number, since it is smaller than the sum of its proper divisors (55765214640).

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

20459906640 is a wasteful number, since it uses less digits than its factorization.

20459906640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2472 (or 2457 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The spelling of 20459906640 in words is "twenty billion, four hundred fifty-nine million, nine hundred six thousand, six hundred forty".