16621037921 has 8 divisors (see below), whose sum is σ = 17763222240. Its totient is φ = 15497128768.

The previous prime is 16621037893. The next prime is 16621037933. The reversal of 16621037921 is 12973012661.

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 16621037921 - 2³⁰ = 15547296097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16621037941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4566911 + ... + 4570548.

It is an arithmetic number, because the mean of its divisors is an integer number (2220402780).

Almost surely, 2^16621037921 is an apocalyptic number.

It is an amenable number.

16621037921 is a deficient number, since it is larger than the sum of its proper divisors (1142184319).

16621037921 is a wasteful number, since it uses less digits than its factorization.

16621037921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9137583.

The product of its (nonzero) digits is 27216, while the sum is 38.

The spelling of 16621037921 in words is "sixteen billion, six hundred twenty-one million, thirty-seven thousand, nine hundred twenty-one".