40640000 has 100 divisors (see below), whose sum is σ = 102267264. Its totient is φ = 16128000.

The previous prime is 40639987. The next prime is 40640009. The reversal of 40640000 is 4604.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (100).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40640009) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 319937 + ... + 320063.

Almost surely, 2^40640000 is an apocalyptic number.

40640000 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 40640000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51133632).

40640000 is an abundant number, since it is smaller than the sum of its proper divisors (61627264).

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

40640000 is an frugal number, since it uses more digits than its factorization.

40640000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165 (or 134 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 40640000 is about 6374.9509802037. The cubic root of 40640000 is about 343.8095213735.

Adding to 40640000 its reverse (4604), we get a palindrome (40644604).

The spelling of 40640000 in words is "forty million, six hundred forty thousand".