61784221 has 2 divisors, whose sum is σ = 61784222. Its totient is φ = 61784220.

The previous prime is 61784213. The next prime is 61784231. The reversal of 61784221 is 12248716.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49632025 + 12152196 = 7045^2 + 3486^2 .

It is a cyclic number.

It is not a de Polignac number, because 61784221 - 2³ = 61784213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61784231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30892110 + 30892111.

It is an arithmetic number, because the mean of its divisors is an integer number (30892111).

Almost surely, 2^61784221 is an apocalyptic number.

It is an amenable number.

61784221 is a deficient number, since it is larger than the sum of its proper divisors (1).

61784221 is an equidigital number, since it uses as much as digits as its factorization.

61784221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5376, while the sum is 31.

The square root of 61784221 is about 7860.2939512464. The cubic root of 61784221 is about 395.3294714112.

The spelling of 61784221 in words is "sixty-one million, seven hundred eighty-four thousand, two hundred twenty-one".