40641209 has 32 divisors (see below), whose sum is σ = 52012800. Its totient is φ = 30965760.

The previous prime is 40641193. The next prime is 40641221. The reversal of 40641209 is 90214604.

It is not a de Polignac number, because 40641209 - 2⁴ = 40641193 is a prime.

It is not an unprimeable number, because it can be changed into a prime (40641269) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 158009 + ... + 158265.

It is an arithmetic number, because the mean of its divisors is an integer number (1625400).

Almost surely, 2^40641209 is an apocalyptic number.

It is an amenable number.

40641209 is a deficient number, since it is larger than the sum of its proper divisors (11371591).

40641209 is a wasteful number, since it uses less digits than its factorization.

40641209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 353.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 40641209 is about 6375.0458037570. The cubic root of 40641209 is about 343.8129306714.

The spelling of 40641209 in words is "forty million, six hundred forty-one thousand, two hundred nine".