39845312640 has 768 divisors, whose sum is σ = 172743217920. Its totient is φ = 8567783424.

The previous prime is 39845312609. The next prime is 39845312651. The reversal of 39845312640 is 4621354893.

39845312640 is a `hidden beast` number, since 3 + 98 + 4 + 531 + 26 + 4 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 18505804 + ... + 18507956.

It is an arithmetic number, because the mean of its divisors is an integer number (224926065).

Almost surely, 2^39845312640 is an apocalyptic number.

39845312640 is a gapful number since it is divisible by the number (30) 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 39845312640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86371608960).

39845312640 is an abundant number, since it is smaller than the sum of its proper divisors (132897905280).

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

39845312640 is a wasteful number, since it uses less digits than its factorization.

39845312640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2211 (or 2187 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The spelling of 39845312640 in words is "thirty-nine billion, eight hundred forty-five million, three hundred twelve thousand, six hundred forty".