19920521 has 2 divisors, whose sum is σ = 19920522. Its totient is φ = 19920520.

The previous prime is 19920499. The next prime is 19920529. The reversal of 19920521 is 12502991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10310521 + 9610000 = 3211^2 + 3100^2 .

It is a cyclic number.

It is not a de Polignac number, because 19920521 - 2¹⁸ = 19658377 is a prime.

It is a super-2 number, since 2×19920521² = 793654313822882, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19920529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9960260 + 9960261.

It is an arithmetic number, because the mean of its divisors is an integer number (9960261).

Almost surely, 2^19920521 is an apocalyptic number.

It is an amenable number.

19920521 is a deficient number, since it is larger than the sum of its proper divisors (1).

19920521 is an equidigital number, since it uses as much as digits as its factorization.

19920521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 19920521 is about 4463.2410869233. The cubic root of 19920521 is about 271.0817189774.

The spelling of 19920521 in words is "nineteen million, nine hundred twenty thousand, five hundred twenty-one".