40399509 has 4 divisors (see below), whose sum is σ = 53866016. Its totient is φ = 26933004.

The previous prime is 40399501. The next prime is 40399511. The reversal of 40399509 is 90599304.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 40399509 - 2³ = 40399501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40399501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6733249 + ... + 6733254.

It is an arithmetic number, because the mean of its divisors is an integer number (13466504).

Almost surely, 2^40399509 is an apocalyptic number.

It is an amenable number.

40399509 is a deficient number, since it is larger than the sum of its proper divisors (13466507).

40399509 is a wasteful number, since it uses less digits than its factorization.

40399509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13466506.

The product of its (nonzero) digits is 43740, while the sum is 39.

The square root of 40399509 is about 6356.0608083938. The cubic root of 40399509 is about 343.1300042402.

The spelling of 40399509 in words is "forty million, three hundred ninety-nine thousand, five hundred nine".