19892021 has 2 divisors, whose sum is σ = 19892022. Its totient is φ = 19892020.

The previous prime is 19892017. The next prime is 19892053. The reversal of 19892021 is 12029891.

It is a happy number.

It is an a-pointer prime, because the next prime (19892053) can be obtained adding 19892021 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15689521 + 4202500 = 3961^2 + 2050^2 .

It is a cyclic number.

It is not a de Polignac number, because 19892021 - 2² = 19892017 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19892071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9946010 + 9946011.

It is an arithmetic number, because the mean of its divisors is an integer number (9946011).

Almost surely, 2^19892021 is an apocalyptic number.

It is an amenable number.

19892021 is a deficient number, since it is larger than the sum of its proper divisors (1).

19892021 is an equidigital number, since it uses as much as digits as its factorization.

19892021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 19892021 is about 4460.0471970597. The cubic root of 19892021 is about 270.9523797174.

The spelling of 19892021 in words is "nineteen million, eight hundred ninety-two thousand, twenty-one".