19921453 has 2 divisors, whose sum is σ = 19921454. Its totient is φ = 19921452.

The previous prime is 19921439. The next prime is 19921457. The reversal of 19921453 is 35412991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19245769 + 675684 = 4387^2 + 822^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19921453 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19921457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9960726 + 9960727.

It is an arithmetic number, because the mean of its divisors is an integer number (9960727).

Almost surely, 2^19921453 is an apocalyptic number.

It is an amenable number.

19921453 is a deficient number, since it is larger than the sum of its proper divisors (1).

19921453 is an equidigital number, since it uses as much as digits as its factorization.

19921453 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9720, while the sum is 34.

The square root of 19921453 is about 4463.3454941333. The cubic root of 19921453 is about 271.0859465144.

The spelling of 19921453 in words is "nineteen million, nine hundred twenty-one thousand, four hundred fifty-three".