19528921 has 2 divisors, whose sum is σ = 19528922. Its totient is φ = 19528920.

The previous prime is 19528907. The next prime is 19528931. The reversal of 19528921 is 12982591.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19360000 + 168921 = 4400^2 + 411^2 .

It is a cyclic number.

It is not a de Polignac number, because 19528921 - 2⁵ = 19528889 is a prime.

It is not a weakly prime, because it can be changed into another prime (19528931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9764460 + 9764461.

It is an arithmetic number, because the mean of its divisors is an integer number (9764461).

Almost surely, 2^19528921 is an apocalyptic number.

It is an amenable number.

19528921 is a deficient number, since it is larger than the sum of its proper divisors (1).

19528921 is an equidigital number, since it uses as much as digits as its factorization.

19528921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12960, while the sum is 37.

The square root of 19528921 is about 4419.1538782894. The cubic root of 19528921 is about 269.2936314479.

It can be divided in two parts, 19528 and 921, that added together give a square (20449 = 143²).

The spelling of 19528921 in words is "nineteen million, five hundred twenty-eight thousand, nine hundred twenty-one".