40689640 has 64 divisors (see below), whose sum is σ = 99043200. Its totient is φ = 14992128.

The previous prime is 40689629. The next prime is 40689641. The reversal of 40689640 is 4698604.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a self number, because there is not a number n which added to its sum of digits gives 40689640.

It is not an unprimeable number, because it can be changed into a prime (40689641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27397 + ... + 28843.

It is an arithmetic number, because the mean of its divisors is an integer number (1547550).

Almost surely, 2^40689640 is an apocalyptic number.

40689640 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 40689640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49521600).

40689640 is an abundant number, since it is smaller than the sum of its proper divisors (58353560).

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

40689640 is a wasteful number, since it uses less digits than its factorization.

40689640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1514 (or 1510 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 37.

The square root of 40689640 is about 6378.8431553065. The cubic root of 40689640 is about 343.9494472315.

The spelling of 40689640 in words is "forty million, six hundred eighty-nine thousand, six hundred forty".