1902221 has 2 divisors, whose sum is σ = 1902222. Its totient is φ = 1902220.

The previous prime is 1902217. The next prime is 1902239. The reversal of 1902221 is 1222091.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1525225 + 376996 = 1235^2 + 614^2 .

It is a cyclic number.

It is not a de Polignac number, because 1902221 - 2² = 1902217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1902221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1902421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 951110 + 951111.

It is an arithmetic number, because the mean of its divisors is an integer number (951111).

2^1902221 is an apocalyptic number.

It is an amenable number.

1902221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1902221 is an equidigital number, since it uses as much as digits as its factorization.

1902221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 1902221 is about 1379.2102812842. The cubic root of 1902221 is about 123.9044746431.

The spelling of 1902221 in words is "one million, nine hundred two thousand, two hundred twenty-one".