16201821 has 8 divisors (see below), whose sum is σ = 22541760. Its totient is φ = 10331552.

The previous prime is 16201789. The next prime is 16201831. The reversal of 16201821 is 12810261.

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

It is a cyclic number.

It is not a de Polignac number, because 16201821 - 2⁵ = 16201789 is a prime.

It is a super-3 number, since 3×16201821³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16201831) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117336 + ... + 117473.

It is an arithmetic number, because the mean of its divisors is an integer number (2817720).

Almost surely, 2^16201821 is an apocalyptic number.

It is an amenable number.

16201821 is a deficient number, since it is larger than the sum of its proper divisors (6339939).

16201821 is a wasteful number, since it uses less digits than its factorization.

16201821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234835.

The product of its (nonzero) digits is 192, while the sum is 21.

The square root of 16201821 is about 4025.1485686866. The cubic root of 16201821 is about 253.0392800432.

The spelling of 16201821 in words is "sixteen million, two hundred one thousand, eight hundred twenty-one".