16505890 has 8 divisors (see below), whose sum is σ = 29710620. Its totient is φ = 6602352.

The previous prime is 16505837. The next prime is 16505911. The reversal of 16505890 is 9850561.

It can be written as a sum of positive squares in 2 ways, for example, as 15864289 + 641601 = 3983^2 + 801^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an alternating number because its digits alternate between odd and even.

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, 825285 + ... + 825304.

Almost surely, 2^16505890 is an apocalyptic number.

16505890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16505890 is a deficient number, since it is larger than the sum of its proper divisors (13204730).

16505890 is a wasteful number, since it uses less digits than its factorization.

16505890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1650596.

The product of its (nonzero) digits is 10800, while the sum is 34.

The square root of 16505890 is about 4062.7441465098. The cubic root of 16505890 is about 254.6124575857.

The spelling of 16505890 in words is "sixteen million, five hundred five thousand, eight hundred ninety".