40128720 has 80 divisors (see below), whose sum is σ = 127789440. Its totient is φ = 10409472.

The previous prime is 40128719. The next prime is 40128731. The reversal of 40128720 is 2782104.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×40128720² = 3220628337676800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6621 + ... + 11139.

It is an arithmetic number, because the mean of its divisors is an integer number (1597368).

Almost surely, 2^40128720 is an apocalyptic number.

40128720 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 40128720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63894720).

40128720 is an abundant number, since it is smaller than the sum of its proper divisors (87660720).

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

40128720 is a wasteful number, since it uses less digits than its factorization.

40128720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4572 (or 4566 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 40128720 is about 6334.7233562327. The cubic root of 40128720 is about 342.3616433727.

The spelling of 40128720 in words is "forty million, one hundred twenty-eight thousand, seven hundred twenty".