1190821 has 2 divisors, whose sum is σ = 1190822. Its totient is φ = 1190820.

The previous prime is 1190809. The next prime is 1190831. The reversal of 1190821 is 1280911.

It is the 446-th star number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1185921 + 4900 = 1089^2 + 70^2 .

It is a cyclic number.

It is not a de Polignac number, because 1190821 - 2⁵ = 1190789 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1190792 and 1190801.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1190831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 595410 + 595411.

It is an arithmetic number, because the mean of its divisors is an integer number (595411).

2^1190821 is an apocalyptic number.

It is an amenable number.

1190821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1190821 is an equidigital number, since it uses as much as digits as its factorization.

1190821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 22.

The square root of 1190821 is about 1091.2474513143. The cubic root of 1190821 is about 105.9942147074.

The spelling of 1190821 in words is "one million, one hundred ninety thousand, eight hundred twenty-one".