19946021 has 2 divisors, whose sum is σ = 19946022. Its totient is φ = 19946020.

The previous prime is 19946011. The next prime is 19946033. The reversal of 19946021 is 12064991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17430625 + 2515396 = 4175^2 + 1586^2 .

It is an emirp because it is prime and its reverse (12064991) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19946021 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 (19946011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9973010 + 9973011.

It is an arithmetic number, because the mean of its divisors is an integer number (9973011).

Almost surely, 2^19946021 is an apocalyptic number.

It is an amenable number.

19946021 is a deficient number, since it is larger than the sum of its proper divisors (1).

19946021 is an equidigital number, since it uses as much as digits as its factorization.

19946021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 19946021 is about 4466.0968417624. The cubic root of 19946021 is about 271.1973390518.

The spelling of 19946021 in words is "nineteen million, nine hundred forty-six thousand, twenty-one".