40420640 has 48 divisors (see below), whose sum is σ = 102844728. Its totient is φ = 14923776.

The previous prime is 40420573. The next prime is 40420643. The reversal of 40420640 is 4602404.

It can be written as a sum of positive squares in 4 ways, for example, as 15460624 + 24960016 = 3932^2 + 4996^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (40420643) 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, 7637 + ... + 11796.

Almost surely, 2^40420640 is an apocalyptic number.

40420640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

40420640 is an abundant number, since it is smaller than the sum of its proper divisors (62424088).

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

40420640 is a wasteful number, since it uses less digits than its factorization.

40420640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19461 (or 19453 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 40420640 is about 6357.7228627866. The cubic root of 40420640 is about 343.1898186332.

The spelling of 40420640 in words is "forty million, four hundred twenty thousand, six hundred forty".