40638720 has 144 divisors (see below), whose sum is σ = 136866240. Its totient is φ = 10248192.

The previous prime is 40638673. The next prime is 40638727. The reversal of 40638720 is 2783604.

40638720 = T₁₁₄ + T₁₁₅ + ... + T₆₂₅.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (40638727) 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, 72682 + ... + 73238.

It is an arithmetic number, because the mean of its divisors is an integer number (950460).

Almost surely, 2^40638720 is an apocalyptic number.

40638720 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 40638720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68433120).

40638720 is an abundant number, since it is smaller than the sum of its proper divisors (96227520).

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

40638720 is a wasteful number, since it uses less digits than its factorization.

40638720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 600 (or 586 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 30.

The square root of 40638720 is about 6374.8505864844. The cubic root of 40638720 is about 343.8059117869.

The spelling of 40638720 in words is "forty million, six hundred thirty-eight thousand, seven hundred twenty".