30780221 has 2 divisors, whose sum is σ = 30780222. Its totient is φ = 30780220.

The previous prime is 30780203. The next prime is 30780229. The reversal of 30780221 is 12208703.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29539225 + 1240996 = 5435^2 + 1114^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30780221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (30780229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15390110 + 15390111.

It is an arithmetic number, because the mean of its divisors is an integer number (15390111).

Almost surely, 2^30780221 is an apocalyptic number.

It is an amenable number.

30780221 is a deficient number, since it is larger than the sum of its proper divisors (1).

30780221 is an equidigital number, since it uses as much as digits as its factorization.

30780221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 30780221 is about 5547.9925198219. The cubic root of 30780221 is about 313.3939280979.

Adding to 30780221 its reverse (12208703), we get a palindrome (42988924).

The spelling of 30780221 in words is "thirty million, seven hundred eighty thousand, two hundred twenty-one".