16400905 has 4 divisors (see below), whose sum is σ = 19681092. Its totient is φ = 13120720.

The previous prime is 16400851. The next prime is 16400927. The reversal of 16400905 is 50900461.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2082249 + 14318656 = 1443^2 + 3784^2 .

It is not a de Polignac number, because 16400905 - 2¹¹ = 16398857 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16400905.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1640086 + ... + 1640095.

It is an arithmetic number, because the mean of its divisors is an integer number (4920273).

Almost surely, 2^16400905 is an apocalyptic number.

It is an amenable number.

16400905 is a deficient number, since it is larger than the sum of its proper divisors (3280187).

16400905 is an equidigital number, since it uses as much as digits as its factorization.

16400905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3280186.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 16400905 is about 4049.8030816325. The cubic root of 16400905 is about 254.0714918521.

The spelling of 16400905 in words is "sixteen million, four hundred thousand, nine hundred five".