16042921 has 2 divisors, whose sum is σ = 16042922. Its totient is φ = 16042920.

The previous prime is 16042919. The next prime is 16042967. The reversal of 16042921 is 12924061.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14745600 + 1297321 = 3840^2 + 1139^2 .

It is a cyclic number.

It is not a de Polignac number, because 16042921 - 2¹ = 16042919 is a prime.

Together with 16042919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (16042981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8021460 + 8021461.

It is an arithmetic number, because the mean of its divisors is an integer number (8021461).

Almost surely, 2^16042921 is an apocalyptic number.

It is an amenable number.

16042921 is a deficient number, since it is larger than the sum of its proper divisors (1).

16042921 is an equidigital number, since it uses as much as digits as its factorization.

16042921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 16042921 is about 4005.3615317472. The cubic root of 16042921 is about 252.2093299301.

Adding to 16042921 its reverse (12924061), we get a palindrome (28966982).

The spelling of 16042921 in words is "sixteen million, forty-two thousand, nine hundred twenty-one".