39997440 has 312 divisors, whose sum is σ = 163557888. Its totient is φ = 8847360.

The previous prime is 39997387. The next prime is 39997469. The reversal of 39997440 is 4479993.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1290225 + ... + 1290255.

It is an arithmetic number, because the mean of its divisors is an integer number (524224).

Almost surely, 2^39997440 is an apocalyptic number.

39997440 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 39997440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81778944).

39997440 is an abundant number, since it is smaller than the sum of its proper divisors (123560448).

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

39997440 is a wasteful number, since it uses less digits than its factorization.

39997440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73 (or 48 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 45.

The square root of 39997440 is about 6324.3529313282. The cubic root of 39997440 is about 341.9878932823.

The spelling of 39997440 in words is "thirty-nine million, nine hundred ninety-seven thousand, four hundred forty".