20667992640 has 448 divisors, whose sum is σ = 70225920000. Its totient is φ = 5142159360.

The previous prime is 20667992617. The next prime is 20667992707. The reversal of 20667992640 is 4629976602.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 138711286 + ... + 138711434.

Almost surely, 2^20667992640 is an apocalyptic number.

20667992640 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 20667992640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35112960000).

20667992640 is an abundant number, since it is smaller than the sum of its proper divisors (49557927360).

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

20667992640 is a wasteful number, since it uses less digits than its factorization.

20667992640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338 (or 328 counting only the distinct ones).

The product of its (nonzero) digits is 1959552, while the sum is 51.

The spelling of 20667992640 in words is "twenty billion, six hundred sixty-seven million, nine hundred ninety-two thousand, six hundred forty".