190921 has 2 divisors, whose sum is σ = 190922. Its totient is φ = 190920.

The previous prime is 190913. The next prime is 190979. The reversal of 190921 is 129091.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164025 + 26896 = 405^2 + 164^2 .

It is a cyclic number.

It is not a de Polignac number, because 190921 - 2³ = 190913 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 190892 and 190901.

It is not a weakly prime, because it can be changed into another prime (190901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95460 + 95461.

It is an arithmetic number, because the mean of its divisors is an integer number (95461).

2¹⁹⁰⁹²¹ is an apocalyptic number.

It is an amenable number.

190921 is a deficient number, since it is larger than the sum of its proper divisors (1).

190921 is an equidigital number, since it uses as much as digits as its factorization.

190921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 190921 is about 436.9450766401. The cubic root of 190921 is about 57.5817111754.

It can be divided in two parts, 190 and 921, that added together give a palindrome (1111).

The spelling of 190921 in words is "one hundred ninety thousand, nine hundred twenty-one".