16633421 has 4 divisors (see below), whose sum is σ = 19009632. Its totient is φ = 14257212.

The previous prime is 16633411. The next prime is 16633423. The reversal of 16633421 is 12433661.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12433661 = 2297 ⋅5413.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16633421 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 (16633423) 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, 1188095 + ... + 1188108.

It is an arithmetic number, because the mean of its divisors is an integer number (4752408).

Almost surely, 2^16633421 is an apocalyptic number.

It is an amenable number.

16633421 is a deficient number, since it is larger than the sum of its proper divisors (2376211).

16633421 is an equidigital number, since it uses as much as digits as its factorization.

16633421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2376210.

The product of its digits is 2592, while the sum is 26.

The square root of 16633421 is about 4078.4091261177. The cubic root of 16633421 is about 255.2665212886.

The spelling of 16633421 in words is "sixteen million, six hundred thirty-three thousand, four hundred twenty-one".