40304640 has 136 divisors (see below), whose sum is σ = 132119568. Its totient is φ = 10485760.

The previous prime is 40304633. The next prime is 40304647. The reversal of 40304640 is 4640304.

It is an interprime number because it is at equal distance from previous prime (40304633) and next prime (40304647).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40304647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 983020 + ... + 983060.

Almost surely, 2^40304640 is an apocalyptic number.

40304640 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 40304640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66059784).

40304640 is an abundant number, since it is smaller than the sum of its proper divisors (91814928).

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

40304640 is an frugal number, since it uses more digits than its factorization.

40304640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81 (or 51 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 21.

The square root of 40304640 is about 6348.5935450303. The cubic root of 40304640 is about 342.8612063010.

Adding to 40304640 its reverse (4640304), we get a palindrome (44944944).

The spelling of 40304640 in words is "forty million, three hundred four thousand, six hundred forty".