16921680 has 40 divisors (see below), whose sum is σ = 52457952. Its totient is φ = 4512384.

The previous prime is 16921673. The next prime is 16921687. The reversal of 16921680 is 8612961.

It is an interprime number because it is at equal distance from previous prime (16921673) and next prime (16921687).

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16921687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35014 + ... + 35493.

Almost surely, 2^16921680 is an apocalyptic number.

16921680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

16921680 is an abundant number, since it is smaller than the sum of its proper divisors (35536272).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16921680 is a wasteful number, since it uses less digits than its factorization.

16921680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70523 (or 70517 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 16921680 is about 4113.5969661599. The cubic root of 16921680 is about 256.7326829307.

The spelling of 16921680 in words is "sixteen million, nine hundred twenty-one thousand, six hundred eighty".