40168728 has 24 divisors (see below), whose sum is σ = 108790500. Its totient is φ = 13389552.

The previous prime is 40168721. The next prime is 40168757. The reversal of 40168728 is 82786104.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×40168728² = 3227053418275968, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 40168692 and 40168701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40168721) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 278878 + ... + 279021.

Almost surely, 2^40168728 is an apocalyptic number.

It is an amenable number.

40168728 is an abundant number, since it is smaller than the sum of its proper divisors (68621772).

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

40168728 is a wasteful number, since it uses less digits than its factorization.

40168728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 557911 (or 557904 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 40168728 is about 6337.8804027845. The cubic root of 40168728 is about 342.4753828187.

The spelling of 40168728 in words is "forty million, one hundred sixty-eight thousand, seven hundred twenty-eight".