400009505 has 16 divisors (see below), whose sum is σ = 549037440. Its totient is φ = 274065792.

The previous prime is 400009501. The next prime is 400009517. The reversal of 400009505 is 505900004.

It is not a de Polignac number, because 400009505 - 2² = 400009501 is a prime.

It is not an unprimeable number, because it can be changed into a prime (400009501) 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, 45941 + ... + 53949.

It is an arithmetic number, because the mean of its divisors is an integer number (34314840).

Almost surely, 2^400009505 is an apocalyptic number.

It is an amenable number.

400009505 is a deficient number, since it is larger than the sum of its proper divisors (149027935).

400009505 is a wasteful number, since it uses less digits than its factorization.

400009505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9448.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 400009505 is about 20000.2376235884. The cubic root of 400009505 is about 736.8121358018.

Adding to 400009505 its reverse (505900004), we get a palindrome (905909509).

The spelling of 400009505 in words is "four hundred million, nine thousand, five hundred five".