1210921 has 2 divisors, whose sum is σ = 1210922. Its totient is φ = 1210920.

The previous prime is 1210903. The next prime is 1210933. The reversal of 1210921 is 1290121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1166400 + 44521 = 1080^2 + 211^2 .

It is a cyclic number.

It is not a de Polignac number, because 1210921 - 2⁷ = 1210793 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 1210895 and 1210904.

It is not a weakly prime, because it can be changed into another prime (1210021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605460 + 605461.

It is an arithmetic number, because the mean of its divisors is an integer number (605461).

2^1210921 is an apocalyptic number.

It is an amenable number.

1210921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1210921 is an equidigital number, since it uses as much as digits as its factorization.

1210921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 1210921 is about 1100.4185567319. The cubic root of 1210921 is about 106.5872531742.

The spelling of 1210921 in words is "one million, two hundred ten thousand, nine hundred twenty-one".