40643665920 has 896 divisors, whose sum is σ = 170425140480. Its totient is φ = 9059696640.

The previous prime is 40643665901. The next prime is 40643665927. The reversal of 40643665920 is 2956634604.

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 (40643665927) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 158146432 + ... + 158146688.

It is an arithmetic number, because the mean of its divisors is an integer number (190206630).

Almost surely, 2^40643665920 is an apocalyptic number.

40643665920 is a gapful number since it is divisible by the number (40) 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 40643665920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85212570240).

40643665920 is an abundant number, since it is smaller than the sum of its proper divisors (129781474560).

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

40643665920 is a wasteful number, since it uses less digits than its factorization.

40643665920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321 (or 291 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 45.

The spelling of 40643665920 in words is "forty billion, six hundred forty-three million, six hundred sixty-five thousand, nine hundred twenty".